So, I was taking a look at the Regent class in the store when I noticed a teensy problem with her warp nacelles.
The warp nacelles are too low. They are not visible from the front of the ship. Big deal, right? Well, it breaks canon in one little way. The intention is that the Bussard Ramscoops (otherwise known as the red tips on most nacelles) are visible from the front so that they can collect hydrogen particles and help refuel the ship.
Darned if I can't find a good source on that to cite, but my internet-fu is a bit dragged down by exhaustion/insomnia.
The Sovereign always towed the line on this one pretty close, but the ramscoops are clearly visible from the front. (and all her other variants follow the rule as well)
I'm sure there are other ships in the game that probably break this rule, but this is the Enterprise and its spirtual successor.
Raise those nacelles.
(yes, I know changing the pylons out probably fixes this, but the stock Regent should be right)