You guys crack me up. The Ultrasone specs are 40 Ohm impedance and 96 dB SPL. Amping is not an epic improvement unless you have a current buffer amp.
The Ultrasones will sound much better than the Beats, though their headband is hit and miss with folks. The AKG's are downright huge with a broader headband, but they have flat bass, so coming off the Beats they'll sound shrill and anemic at the same time... though they're actually fine. If you actually liked your Beats (which many do) then don't get the AKGs; they're too real. The Ultrasones will be spectacular and are actually portable. The S-Logic is awesome. It's the only thing that can really rival AKG's wide soundstage. Anyway, they don't really need amping to sound good, but they make use of amping to sound a bit better, especially with quiet tracks.
I've seen a very detailed electrical analysis of FiiO products and the E7 is by far better than the E11. The output impedance of the E7 matches the Ultrasones perfectly... much better than if you mate it to the E9 dock. The S-Logic will be your best friend with the E7.
Also, the Ultrasone Pro 650's or 750's sound VERY similar for less money. So if you're feeling the squeeze, they're great options.
Enjoy!
Oh, if you like the Ultrasone sound but want some semi-open cans, then the Pro 2900's are good, as are the AKG K240 or K242 headphones... very similar in sound and detail. The AKGs aren't portable, though. They also look a little funny but they are probably the most comfortable headphones on earth.