I'm did a review a while back of the Brammo ENERTIA. That's Brammo's entry-level cycle. You can see the review of that at:
Review: Brammo Enertia electric motorcycle
I also briefly test-rode a ZERO as well, but never had a chance to really do a full review.
The Empulse is definitely the big-brother version of the Enertia. It seats two instead of one. The top speed is nearly double. More powerful motor, better acceleration, and J1772 level-2 charging on a cycle is pretty neat as well.
I liked the shape, feel, and ride of both cycles. One advantage of the more basic Enertia is that since it is clutchless, I was able to ride it when I had a broken left foot.
I've also thought a little about high-performance EVs since this past Friday, when I had a chance to drive a Tesla Model S. Part of it is that you really do get what you pay for. The high-end stuff is NICE!!! It's VERY cool to have that kind of acceleration. On the other hand, if you aren't an aggressive driver and actually drive within speed-limits the way you ought to, a Nissan LEAF is a very nice car that gives you an EV grin, just like a Tesla would, but at a much lower cost.
Likewise, an Enertia is less expensive than the Empulse, and is a great commuter bike. It all depends on what you are looking for.
Frankly, there are lots of great EV cars and cycles out there right now. I don't think I've driven a single one I haven't liked. Oh, I might not like the design of the back seat on the Volt, or the price of a Tesla S, but the vehicles themselves overall are really fantastic.
The Empulse and Enertia are really two different classes of motorcycles. They are both nice, but yes, the Empluse gives you more power and the manual control over the transmission is one more fun thing to play with.