A lot of poor advice here, unfortunately. While they have quirks, most cars do. Best to head over to Volvospeed.com, Turbobricks.com or Swedespeed.com and ask people with more experience.
The angle gears are only an issue if someone had a leaky gear case, or if you're making 450 horsepower and launching hard at drag strips...it's pretty easy to drop and re-seal (uses anaerobic sealant). Regular driving on a well-maintained car and you won't ever have an issue.
AWD slow to react?! It's nearly instantaneous, requiring as little as 1/15th of a wheel revolution to engage. It received a lot of praise when it was released. Haldex is used in some of the world's fastest and most powerful sports cars. The ones that sucked were 1st Gen XC70, which didn't use Haldex.
We currently have an '05 with 130k (as well as a 95 940 and 85 240). The 2nd generation Haldex AWD is really pretty good assuming you aren't rock-crawling. The Aisin-Warner transmissions in the P2 Volvos (2001-07) were unfortunately troublesome and clunky. Fresh fluid, external cooling, and software updates from the dealer will be the best ways to avoid trouble and make it as smooth as possible. Still, they can feel "confused" about shifting from N-1 and 1-N.
The engine itself is robust, powerful, smooth, and sounds amazing uncorked if that's your thing. They are also easy to modify; my last Volvo 5 cylinder was making 349hp to the wheels. In stock form, it's torquey down low and adequate, but top end passing power won't amaze you.
Do more research on enthusiast forums. These cars can be VERY expensive to maintain if you aren't willing to do a little homework and research. But if you're mechanically inclined and you can navigate the internet well, it will put you 1 step ahead.
In short, this will make a nice, fairly fuel efficient fire road explorer. But if you do any serious wheeling, this should be the daily commuter and not the ExPo rig.