the difference in tone is not enough to matter unless you are a pro in a studio listening to every nuance thru a set of $2500 headphones.
I know alot of people who are VERY happy with their Gibson les Pauls... do not spend too much time listening to what someone else says ...go try one for yourself,,,check it out.
the difference between a les paul standard and an es335 are huge. totally different guitars. If your not even sure what type of guitar you want I say go check some out at your local shop
chambered simply means that some of the internal wood has been removed to provide more resonance and it also makes the guitar lighter.Some of the "old school" players don't like Gibson changing anything so thay don't like their guitar chambered...no matter what small difference it makes.