Hey guys my bros looking for a new bike and he wants to know if the Kona Blast is better than the Secialized Rockhopper?

Better for what?

if he feels more comfortable on the blast, then yes. if he feels more comfortable on the rockhopper, then no.

i guess it was a stupid question

There are no stupid questions...only smart-a$$ answers.

What type of riding are you (or your brother) looking to do?

my brother aand I are into fast pace trail riding, I think its xc.

I don't have any expeirience on a Blast but do on a rockhopper. It is a great bike, can't go wrong with it.

I would say Rockhopper, although i've never tried either, i think the brakes on the Rockhopper are better too.

I don't think it matter so much because both those brands are very competitive and provide great bang for the buck. What matter most is going to be the LBS's ability to size him up and setup the rig before he takes it off the showroom floor. Can't emphasize the size enough because there's usually no turning back if you buy the wrong size bike. Check to see if the stand over is enough, see if the seat and post will adjust to his liking, and see if the bar needs to be swapped for a riser bar.

Any good LBS will go over the entire bike before letting their customer take the bike. Such as brakes (see if they're rubbing/binding, and see if they're enough bite and lever feel), see if the derailleurs are shifting smoothly, and see if the shocks and tires have enough air.

size is a big deal considering he is 6.5

i'm pretty sure they both come in multiple sizes. go to the shop and try them out.