I'm pretty happy with my Norco-X6 frame I picked up for cheap. I've built it up with a Fox Talas fork and a triple chainring.
The single pivot makes it a little harsh in the rear end, but I wanted the ease of maintenance of only two bearings. Trust me, when you shell out for 8 bearings for a Santa Cruz you'll know what I mean.
The forks are only 32 mm so they flex a bit under duress. A bigger front end with 36mm stauncions would be nicer with 160/170mm travel to soak things up.
That said, it makes a great, simple to maintain playbike, that can be ridden to the top of the hill and bombed back down.
I'll add my support to those who've recommended the Reign. A couple of friends have the Giant, which does everything the Haro does but is faster and comfier down hill. One of these guys took 8th in sport at the Yackandandah round of the VICDH series last weekend, so you can assume they are a capable bike.