Holly, There is a huge difference between "not" having a slide-out, and having a slide-out in the stored position. No doubt, a slide-out opens the interior which is especially nice for bigger people and/or travel with larger dogs.
For reference, here is our 2350 with no slide-out. Yes it's tighter, but much better than having the slide-out in the stored position.

You gain an extra 12"-14" of linear wall space to be creative with when you have a dinette without the slide-out by utilizing the angled transition wall as shown.

My point here is that there are options to think about. If having more floor space is more important, then by all means, get the 2552 with a slide-out. The dinette will be a bit tighter and you will sacrifice the extra pantry.
For dimensional reference, I am 5'-11" tall and can fully stretch out on our dinette when made into a bed. My feet touch the one end and my hair touches the other end.