You are correct about what swapping you can do with a verizon pre2 vs an unlocked pre2.
Originally Posted by RyanCell
I had a verizon pre2 to work with, but still decided to swap the whole back anyway because it's just that much easier/faster to do, and because my sprint back seemed to be in decent shape (so why mess with it?). I just blew/wiped away any dust or debris from it before installing it into the pre2...flawless results.
I guess if your old back has something that totally busted in it (buttons, speaker, headphone jack, antenna, etc.), or if you really want everything spanking new, then def get a verizon pre2 and swap just the comm board itself. Otherwise it's not a big deal. Buying a verizon Pre2 will at least give you the option (whether now or later), but don't go spending much extra money for it.
Keep in mind that from the outside, your phone will still look brand spanking new no matter how you do the swap, since you will be using the back battery cover from the Pre2 anyway.
I forget if it was already posted in this thread, but here is the official instruction link for doing a frankenpre2 swap. It shows you the method of swapping the whole back.
Swapping just the actual comm board itself would additionally involve bending up the little metal flap on the comm board, detaching the black and white antenna wires, reattaching the comm board to the black and white wires of the new back bezel, and then bending the metal flap on the comm board back down. These additional steps would take place between Step 10 and Step 11.