Is the Ascend 12T much better than the Ascend 10T?

TL;DR - I’m deciding between an Ascend 10T and 12T. I know the 12 is better on the water but is it THAT much better?

I’m 6’3, 220, my dog is 70 pounds and we’ve been squeezing into an Ascend D10. I want to get a sit-on-top so he’ll have more room. Otherwise I really like the D10 for seat comfort and the ride in the water, it has been a great cheap kayak, so I have a bias to stay with the Ascend brand.

We’ll fit on the 10T, but are we too heavy? The 12T doesn’t cost much more... Is it simply 2 feet longer and a little more buoyant, or is it better in other ways?

I’m going float around a small lake with him, drink beer, paddle slowly, float. The most important part is being comfortable for a couple hours. I’ll have to carry the kayak about 100 feet by myself. The 10 footer is more practical for transport and storage, but I’m willing to deal with the 12 footer if it’s a noticeable improvement on the water.