For me, it's probably damn near perfect in terms of form factor. It took a day or two to get used to holding it, but after that it's been nothing but awesome. The extra real-estate is really appreciated. I'm a bit faster at thumb typing because the spacing is a bit more comfortable.
I dig it.
That said, the bigger screen is absolutely wonderful for browsing and reading in general; I much prefer Chrome on the GNex to my wife's iPhone 4S.
It's a taste and usage thing. I find for my needs it works very well. Someone who does a lot of one-handed work (while, er, driving maybe) is going to want a smaller phone.
The _only_ size related gripe I have is when I am using it one handed and need to reach the upper left corner with my thumb. That's kinda tough. That and it doesn't fit in my skinny jeans.
Also the "theory" that everything above 3.5" is too big for one-handed actions is completely untrue. I have average hands, and I could easily use the GS2 with one hand, even up to the top.
It seems to be based on the standard launcher, but allows you to customize a lot of things, including the search widget.
EDIT: Whoops misunderstood the question and gave a completely wrong answer. See replies.
How to remove it (not without complications): http://www.addictivetips.com/mobile/how-to-disable-hide-goog...
I thought the Nexus S size was perfect, but the Galaxy S II is tolerable.
I find the phonearena.com size comparison tool really handy. http://www.phonearena.com/phones/Samsung-GALAXY-Nexus_id5595...
I'm also pondering getting an HTC One S.
So take that for what its worth. Don't be surprised if Google ends up allowing carriers and manufacturers to provide more customization with Nexus phones and be more lax with update timelines.
Hmm. Are there any GNexus owners our there that can tell us about the size of the device? It's the one real sticking point I have with it.
EDIT: For anyone else that's wondering, I looked up the refund policy. They pay return shipping, but you pay a 15% restocking fee- $60, pre-tax.