Well everyone else is diving in and having a say, so here it goes!!
I didn't try to take the ST11 film too seriously and therefore I enjoyed it

. The only frustration I had with it was the messing around with scale whether that be with the Enterprise or the Mayflower saucer. That aside I think it managed to successfully combine a modern look with certain retro elements from the original series. It completely avoided feeling like dull, tame, safe TV movies that Generations and Insurrection were.
Now back to the Enterprise. There are things I don't like about it - primarily the nacelles and the secondary hull. It doesn't have the elegance of the TMP Enterprise and what I personally would have liked to have seen was a
more elegantly styled TMP-based Enterprise with a few retro elements (not necessarily related to the TOS-Enterprise). Yet strangely enough I do like Ryan Churches concept drawings for the Enterprise (
http://www.ryanchurch.com/startrek11), which have a more 50s retro look about them. Something got lost in translation.
Concerning the size - at its largest it feels too big and I think that messing around with the scale does impact the film. Why? Because to me the Enterprise is a character in the film like Kirk, Spock and Bones. Flesh and blood characters come with emotions, motivations, loves and hates. It gives them depth and we take an interest in them. The Enterprise being fictional nuts and bolts doesn't have that. Instead its depth or personality comes through its look, size, functionality, reliability, battle scars and the environments it's placed in.
With a major flesh and blood character, we shouldn't expect sudden changes in their personality purely for reasons of dramatic effect unless the story demands it (i.e. some traumatic event - tourture or a death). An actor lays down a personality for the character and will probably change it suddenly for the above reasons or gradually to convey the passing of time (i.e. maturity).
So with the Enterprise, you would expect the same approach. You give it a personality and then you stick with it. Some aspects of that personality will be flawed (i.e. design shortcomings, size), but you learn to exploit the flaw in the story or if a scene doesn't work you avoid or rewrite it.
When fans say they are comfortable with a ship of size xyz ft, it's because they are trying to base that opinion on a fictional advancement in technology in the 23rd century and what they want the ships personality to be. Some want a really big mean badass ship (Goliath) and others want a smaller, more believable fragile ship that succeeds in a fight against the odds (David). Personally I prefer the latter. Problem is that varying the scale during the course of a film could give the ship a split personality.
Well that's enough said. I would like to see more artwork posted here on what people feel would improve the JJprise (not just pics of the TOS-Enterprise

).
Cheers,
S.O.