Tell you what, firelance. I picked the ud3h, but won't have it put together until the 17th or so. If you can wait, I'll let you know if I have any issues. But that doesn't really answer your questions about which to get...
I would stay away from combo deals altogether, sometimes they don't honor the warranty for a combo deal. You may want to inquire Micro Center on the return policy on combo deal as well.
As for the mobo, I'd go with Gigabyte UD5H
They are not packaged together. It's a retail boxed MB and CPU. Warranty is the same as separate. The deal is just discounted for purchasing both items at the same time. I bought the Asrock Pro 4 and the 3750k yesterday and it looks like the PCI-e slots are bad and the board needs to go back.
I got my build all put together, and so far the UD3H is performing great. For my first time overclocking, it let me get my 3570K up to about 4.3 holding around 65 degrees with a Hyper 212 EVO. No problems with the audio yet, but I don't have a surround sound speaker set up to really test it, only a basic 2.1 setup. And even with the Hyper 212 blowing in a push setup towards the rear exhaust, there's enough space to use all 4 of the DIMM slots, even though I'm only using 2 Mushkin Blacklines. I have no idea what the compatibility issues are if you did want to use all 4, however.
In hindsight, I kind of wish I'd save the $10-20 or so and went with the Extreme 4, but it wasn't in stock at the time. While I'm using most of the USB 3.0 ports on the back, I don't have a single 3.0 device so having 6x 3.0 ports wasn't necessary, and I am very unlikely to use the mSATA feature either. But having the dual bios feature is nice on the UD3H. For the OP, these are all features that you need to consider.