One thing really stands out in HD. It's the interim uniforms they used in the first half-dozen or so episodes. The vertical and horizontal seams on the front and back are pretty distracting. I've always noticed the vertical ones, but I never noticed the seams near the armpits before.
Starting in Booby Trap, Picard gets the newest and final uniform. Riker gets one in the next episode, The Enemy, while the yellow-shirts get them later.
In Booby Trap, I didn't notice a CGI Enterprise. I did notice the new explosion for the warship and collectors. And when the Enterprise fires the torpedoes, they flipped the hull registry to its proper orientation (which HTV forgot to do in Pen Pals - they left it blank)