2) You need PS but your primary software runs under Linux.
That’s the reason I tried it. The original poster asks about Xandros, which I’m pretty sure just bundles a copy of Codeweavers WINE. I bought Codeweavers WINE a few months back to run on my SUSE desktop. The main purpose was to have easy access to Microsoft Word, but I tried PS7 as well.
Word runs like a charm. It’s one of Codeweaver’s "gold applications" which means they expect it to run flawlessly, and they want to know if it doesn’t.
PS7 is a "silver application" which means it pretty much works, but it hasn’t been tested to any great degree. I found it "not good enough". It does work for the vast majority of the time, but the odd bug makes it unusable for real work. For example, select the marquee tool and set it to fixed aspect ratio, and you’ll find you can’t change the numbers in the toolbar! I found a handful of weird little things like that, and with a program like PS, bugs in the interface make it very hard to use. 100% is good enough, anything less is largely unusable.
As for speed, I’ve never run Windows on that box, so I can’t compare directly. However, performance matches what I’d expect from a native Linux application running on the hardware. It’s a dual processor box, and WINE likes dual processors. WINE is, in many areas, a faster implementation of the Windows libraries than is found on Windows, and the underlying subsystems are often superior too – especially the disk and memory subsystems. Performance under WINE will normally be around equal to performance under Windows on the same hardware.
I have my vote on Codeweaver’s website for better application support set to Photoshop. If they get it to the standard MS Word is at, it will be a genuinely usable solution, at least for web graphics work. However, Lotus Notes is the application the vast majority of people want supported, so PS will have to wait. :o(