The SVD is my crawl in the mud gun. I use it in the water logged or messy fields that I know I will be crawling around in for hours. Dings or scratches on it only make it more Russian. xD I have to say, I wish I never sold my AtoZ. The A&K can certainly be nice after a little work inside, but the external quality just isn't near what my AtoZ was.
The PSG1 and WA2000 I use in urban environments. The PSG1 just has is far to much of a hassle to strip down and clean out if in the mud, and I would probably break down and cry if I found a ding or scratch on the metal or wood of the WA2000.
The M82....well... That thing is far to much of a hassle to mess around with in really any type of environment, and it just doesn't have the accuracy to make the hassle worth it.
The PSG1 is one of the two I had. I sold the first one because the trademarks were ground off and upgraded this one myself. Inside it is a 11.1 Lipo, Systema Mosfet, 300% Systema Full Tune Up Kit, PDI Chamber Block, Mabull bucking, concave spacer I just made myself, and a polished stock barrel. Probably so far the only AEG I have ever liked.
My favorite of the four has to be the WA2000 of course. The accuracy it puts out just completely overlooks it's weight, lack of sling possibility, and impossible to source mags. Once I finish up gunsmithing school, I may take on the challenge of making fiberglass furniture to replace the Walnut on it. That way I have no worries of dings in the wood and I can make it my full time skirmish piece.