Frame differences in same series?
 

I just got back into MTBing after a little bit. I could never afford a really good bike...my last bike was a Trek 820 and now, I just got a Haro VSE for a really great price. that being said, I can never leave anything stock. Are all the Haro V series frames the same with the price differences being the components? I'm asking cos I'd like to upgrade a few things on this bike but I don't want to go too far if the frame isn't really worth keeping.

For one, I"d like to get a better fork and some better shifters. I have an Acera rear derailleur so I think I'll be ok with that for a while.

Would this be an ok bike for all around trail riding with some jumps thrown into the mix and maybe some downhill? I'm pretty much going to be trying out a bunch of different stuff with this bike so I'd like to make some upgrades that will be good for anything.