I've never understood the complaining about the larger sizes.
- She looks like Kirk's Enterprise from TOS -- arguably better depending on personal preferences
- She does the same things; she has phasers, photons, transporters and warp
- the added size can be better in regards to adding new capabilities down the line (imagine this becoming a show after the movies run?)
- the size scales up just fine
- Star Trek itself has done this about a zillion times before, so it's actually expected for things to change size. :P Must be due to their mass lightening technology. :P
Now, you have Vengeance.
Enterprise and her ships technically sucked bad when facing Narada -- Narada was defeated by outwitting her, much like how most of Trek goes for the Federation.
Enter a bigger ship, which hopefully may not suck as much if another threat like Narada comes alone. No one really wants their planet sucked into a black hole after all. Which Earth was on its way to becoming, except for future tech in the form of Jellyfish, which they lost and have no way of recovering.