Quality of RISCOS software
While RISCOS software may not always offer the features of PC software, what is usually missing is the stuff you don't need. Any lack of features is usually more than made up for by the technical support that is available. It is always quicker and easier to use than PC software. (I think a lot of people are confusing familiarity with ease of use, I have even seen a comment that MS Word is easy to use. Analogy: Is a clutch on a car easy to use?) Most of it will also run on old 3.1 systems, which can be useful as a backup.
RISCOS outdated?
It has the best user interface, I have ever used. I would prefer to use RISCOS 3 than any version of windows. The graphics (on 3.5 +) make a Mac look like a PC. Start up time is so much better than a PC or Mac that you could almost have finished a short job in the time saved. There are some nasties, but they are generally down to the system being over simple rather than over complex. There are some major omissions from the OS, (most of which can be bought from Warm Silence or R-Comp).
The printing and file system are horribly slow
This is the most justified criticism. I have seen the performance of the file system compared to an XT PC, I think this is unfair, I think it performs as well as a good 286. I understand that the problem is a combination of old bus design and the single threaded nature of the file system. However in use this very rarely shows up because the OS is so efficient. I spend far less time, proportionally, cursing the delays waiting for the file and print systems on the Risc PC at home, than I do at work while waiting for the PCs to do anything (and at home it's my time.)
Virtual memory
Why? My RPC has 64M, I don't think I've ever managed to get less than about 20M free. As I am writing I have over 48M free. Not having it will encourage programmers to keep code efficient. (We certainly don't want it while the file system is like it is now.) Pairs of second hand 8M FPM simms are so cheap that no-one with a RiscPC should have less than 16M. Pairs of sixteens are also readily available for not too much, and pairs of thirty twos can be found without breaking the bank.
Pre-emptive multi-tasking and memory protection
Both are desirable, but not at the cost of compatibility with old applications. Again the lack of them forces better code writing (otherwise the thing locks up). These are of more concern to "power users" than ordinary users. Hopefully they will appear in RISCOS 5, but it's hardly the end of the world if they don't.
Industry standard files and user interface.
This is no worse than not using the leading product on a PC. Most new programs support industry standard file types, for example EasiWriter for Word. (Although it would be nice to see the rest of MS Office files types being directly useable.)
I would like to point out the disservice a lot of schools did their students by abandoning Acorns around 1994 to go to Windows 3.1 using the "Industry standard" argument. These students would have had to have undergone the transition from Windows 3.1 at school to Windows 95 at work, which is a much bigger change in interface than going from RISCOS 3.1 to Windows 95.
Internet software
The new !DialUp from R-Comp is excellent. Less grief than a PC. Messenger Pro is extremely good too, and doesn't catch KAKWORM etc. FTPc is better than anything I've seen on a PC. ICQ, riscster and MP3 radio all work quite nicely. The only major weak point is the browsers' inability to correctly display all pages. This is mostly down to web pages being written for IE 4 and above, rather than in straight HTML, and lack of plug-ins. The plug-ins problem is not insurmountable, a reasonable version of flash is available for example. The web page compatibility is no worse than using IE 3. When pages work properly, the rendered pages look far better than on a PC. (It is always nice, to see people's faces when they see the display on my five year old Risc PC and compare it to what the new heat belching monster in the corner of their room manages.) All the browsers are quite nice to use and reasonably fast. ArcWeb has the most useable interface of any Browser I have ever used.
Not buying a new RISCOS machine because of lack of confidence in the future.
This is the one I have the most trouble getting my head around. If you buy a new RO machine you can be confident that you will have several years easy use out of it, even if RISCOS ltd. were to fold. (Which seems unlikely anyway). If you buy a PC you can be certain that in six months it will be obsolete. (So certain that the government now allow for 100% depreciation on IT kit in a year, which is a damn good reason to buy a RISCOS system, - beat the taxman.) You could probably afford a reasonable night out with the cost of electricity you would save in a year by using an ARM instead of a Pentium III. (That would deal with one of the evenings you would save by not having to re-install windows.) You can also be sure that due to the size of the RISCOS market, it is very unlikely that you would encounter a cowboy trying to rip you off.
Not upgrading to RISCOS 4
RISCOS 4 is great, faster and easier to setup than 3.5. Anyone with an A7000 or Risc PC, without it should upgrade. Very little software doesn't run on my system, and most that doesn't, won't run because of the Strong Arm not RO 4. The only program I have with a major problem is Tots TV, (and commenting out the CD accelerator in the run file fixes that).
I used RO 3.1 about six years ago at when I worked at a school. I was using GEM on a PC at home at that time. I became a computer engineer (MCP in Windows 95, which I liked initially because of its resemblance to RISCOS, I hated Windows 3.x). About three years ago I got a Risc PC, I loved the machine but didn't find RISCOS 3.5 as nice as 3.1. The machine was mainly an interest (I did use it to make web pages), a PC being the main workstation. Just over a year ago I became aware of the security loopholes in the Microsoft internet products. (A few months before melissa, kakworm etc. did the rounds). I decided to only use the Acorn on the net and bought Messenger pro and Webster XL. A couple of months later I bought RO 4 and a Strong Arm. There was a delay in supplying the Strong Arm so I got to make a direct comparison between RO 3.5 and 4. It is noticeably faster, to start and when running. It is also much nicer to set up. The PC got almost no use after I got RO 4. When I fitted the Strong Arm (the fastest upgrade I have ever done to a computer - less than a minute to have a running system) I started becoming very frustrated with the perfomance of almost every PC I used (The exeptions being some 500MHz machines with 128M RAM running NT4, they're not too bad.)
I have started up a small web design business with friends using RISCOS systems. One is currently using a second hand A7000 he got from AJS. His main problem with getting used to RISCOS compared to Windows, is getting used to not having to do things in a convoluted way. Unzipping a file was a problem, double clicking on it and dragging what came up to where he wanted to put it, was just too simple. He was expecting have go through various menus etc.
A final thought: if I had to use a PC to do the web design, I don't think I would have bothered to start the business.
For an ironic comment on why people should keep using pcs at work look at: http://www.kentwebnet.org/computers/why.htm