a predator with autocannon turret & heavy bolter sponsons is dirt cheap pts-wise and will absolutely murder most infantry! even space marines will feel it as you still throwing 8 shots/turn at a squad...
plus, you can keep on the move and still fire everything to full effect!
the land raider is a bit much in anything 1500pts or below. it's simply too much of a 'all your eggs in one basket' approch IMHO.
now, that's not say you can't build an army around the tactic of say, a land raider born assault... but you'd need to re-design your list specifically with that goal in mind! (ie: have dedicated units which will eliminate any possible threat to your precious land raider!)
cheers!