The big problem I have with all d20 games is the steep rise in power level as one gains access to the options one needs to make a character concept possible at 6th or 8th level.
Which is the reason that got us E6.

However, severely limiting BAB, removing saving throw bonuses, and skill ranks should make a real difference in that regard, which so far is what is really selling me 5th Edition.
Out of the box E6, count me in!