I had the opposite with an AR- the thing was so tight it didn't run well until a couple rounds went down the pipe.
The RFB is awesome, it's a non-restricted 308 bullpup ffs! Ammo is expensive compared to .223, reloading takes the sting away, but if you're looking to dump a lot of rounds downrange, it'll still cost you.
The tavor is awesome too! Non-restricted 5.56 bullpup! The trigger sucks, but it doesn't make the rifle unusable. I took epoxy's advice and do mag changes his way and they're quick. Some people complain about getting gases in their face, it doesn't bother me that much.
5.56/.223 is cheaper than 308 and you can use 10 round LAR mags. I won't sell either of them. I love them both, and don't know which one would suit you better.
For big game hunting and plinking-RFB.
For varmint hunting and plinking- tavor