I actually kind of like the look of the proposed new ship, but I think that's because I like the low-slung warp nacelles. I think Starfleet should have a Starfleet carrier - yes, there's the Atrox, but that's a ship from an allied government, not specifically a Starfleet ship.
I'd also like to see a Starfleet cruiser with the launch capabilities of the Armitage/Vesta.
Lastly, I'd like to see a "free" carrier for the F2P folks. It doesn't have to be as cool as the existing carriers, but give it something like 3 front/3 back/1 launch bay (6 Peregrines)/3+3+3 console slots, Lieutenant Eng/Sci/Tac slots, Commander and Ensign Universal slots. Call it a Patrol Carrier.
That design is almost better than the original Odyssey.
The Somraw, K'tinga, D'Kyr, D7, Kumari, Xindi carrier, Xindi escort, and the T'Varo are all older than the Constitution Refit and yet they are tier 5. The Constellation is made up primarily of Connie refit parts and it is tier 5, there is no logical reason whatsoever for the no tier 5/6 connie rule.
I will not go into the detail about what I was thinking when I saw the lower dorsal area, but let us just say, it is a very manly hull.
Overall I like the idea but I do not think we will get any Fed ships soon, as the Romulan faction is a bit short on choices (no carrier, no flag ship or destroyer. Most T5 are refits of lower tier hulls)
The Atrox needs a fleet version first off, and then maybe you could start to look at Fed "Heavy Carrier" but some will say including me, that the Atrox, fills the Fed Heavy Carrier slot, and the Escort carrier fills the light carrier slot. Not to mention the Vesta, which has a single launch bay.
I am a carrier player, with the Atrox, Vesta, and Escort in my ship slots. Give the Fed players a Fleet Atrox and then the problems are solved.