According to theory, the new Megas with outboard bearings are supposed to be somewhat stiffer. Personally I have an ISIS crank, and that puppy is so stiff, the frame flexes way before the BB does.

The Megas have some really cool bling factor. However, the Gossamer Mega compact weighs more than an Energy compact w/Platinum Pro BB. Just some food for thought. I like both of them alot. For the same price range, if was trying to save weight, I think I would go Energy. If I wanted more bling, I would go Gossamer.

I think it really just comes down to personal preferance, and what you want it to look like.

Another option is to use the Energy crank with the new Mega-Tech BB's. They are ISIS BB's that use the same outboard bearing design as the Megas, but they are not integrated to the crank, so you can switch cranks if you want in the future without having to remove the BB.