Originally Posted by Sierra_rider

I'm a proponent of the modern geometry, regardless of the rider's skill level. Whatever terrain you intend to ride, is going to probably be the biggest factor in how slack/progressive of geometry you want. For reference, my Santa Cruz Blur is the "downcountry"(120mm fork) spec of their full-suspension XC bike. It has a head tube angle of 67.1 and a seat tube angle of 74.9 in size large. The regular Blur(100mm fork) is 68.3 for the HT and 75.8 for the ST. Either of these bikes have pretty "normal" numbers for a modern XC bike(but would be considered slack compared to virtually all the older bikes,) and are perfectly at home on twisty trails that don't feature too many technical features. They can handle some more technical terrain, but I'd describe the handling as "nervous" in those situations. Even at that, they'll completely outclass the old school 26"ers in technical terrain.

The Blur is completely out of your price range, so I'm not recommending it...however, I think it's a good reference point for the geo to look at on a more XC-oriented modern MTB. Expect a "trail bike" to have a HT angle that's a degree or 2 slacker and a ST that's a similar amount steeper. Either style of bike is fine for any skill level on most non-technical trails.