Welcome to the forum! And thank you for commenting about your new izip Zuma.
Also glad to hear you confirm what I suspected all along about the difference in motors between these bikes. Actually surprised to hear you say you like the power of the 36v Zuma better than the 48v Pedego! I thought for sure the 48v direct drive would at least equal the power of a 36v geared drive.
Other than the noisy brakes, if you are in the market for a street legal 20mph ebike that can climb hills, the Zuma is a great value. If I had to do it all over again, and price wasn't an issue, I would get myself a bike from Hi-Power Cycles. http://www.hi-powercycles.com/product.sc?productId=36
But, I just can't justify the extra cost when all my needs are met with my Zuma.
No complaints here with the welds on my Zuma and both wheels look true to the eye when spinning them upside down. Sounds like you may need to have your wheels trued. Something to note is when my bike arrived via FedEx, it was DOUBLE boxed, HEAVILY padded and the box had no indication that it had been mishandled. This was not the case with my first ebike back in 2007, shipped via UPS, single box, with parts hanging out upon arrival.
About the PAS, it scared me a few times when the motor kicked in while making sharp turns, or while on loose gravel. That motor will surprise you. But this is why the bike has brake inhibits! It might scare you once or twice but you get used to it. Do what I do, use PAS for uphill or downhill going straight, and TAG for everything else.
I am very glad I went with the Zuma for another reason; it is easy to verify as street legal. Today I counted 5 police cars out collecting money to pay for their new over-sized police station from unsuspecting drivers in the five miles I commute. As I traveled the 14 traffic lights on my way home, I had the pleasure of their shiny new police cars accompany me through 8 of the traffic lights. For my safety of course. I laughed as I kid to my self... sir license and registration please. Do you know why I pulled you over? Since I obeyed the traffic laws, and the bike is legal, I have no worries and so far, no hassles.