Mike,
Sorry it took so long to reply, I've been pretty busy as of late.
Like you said, the 3525 is a heavy tractor, and with the ag tires on soft ground, it does leave tracks. Actual damage is just as much operator technique as anything else, but making sharp turns on really soft ground will definately do some damage, the front wheels more than the rears. I've never had my loader off of the tractor yet, but removing it will lighten things up quite a bit, as the entire loader weighs around 1400 pounds I think, removing it should take off probably around 1100 or so, just guessing. On dry, solid ground, they're typically not a problem and don't cause any damage to speak of.
If you keep the blades sharp on the 'hog, they can do a fairly nice job of cutting also. I wouldn't use one for my front yard, but for waterways and such, that might be all you need (without seeing what you're talking about).
For finish mowers, what size are you looking for? When I bought mine, I got a 72", just because that's all my old 8N will handle, but I think the 3525 would easily handle a big 8 foot mower. When my KingKutter finish mower finally dies (don't know if it ever will...) I'm going to upgrade to a 7' mower, as that's the biggest I think I can get into my shed. Or else I'll have to build a bigger shed.
As far as mechanicals, I think they're all pretty much bulletproof for the most part. I'm just over 50 hours (just starting to get it broken in) on my 3525, and no initial problems yet. We'll see how it goes when I get a couple thousand hours on it
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