Was on the Infinity, and saw the Sky Suites, they are quite large (251 sq.ft.), with a veranda of 57 sq. ft. The brochure for the Summit shows that amenities are many, sounds worth it to me.
We didn't go that elaborate, but are booked in a 1A for Nov 23rd sailing.
I don't think you will be disappointed.
I would be perfectly happy with the A1. I caught a glimpse (1" x 1" photo) in the 2002 Alaska brochure on the Infinity page. It looked very nice!
Problem is that we are spoiled by HAL's full suites. My mother doesn't want to give up breakfast in cabin and priority embarkation.
Planning for Alaska and researching a new line and a ship that isn't even in service yet is making me bonkers. We have done the Caribbean 4 times so it's easy to book and plan. I know so little about Alaska and Celebrity that I feel like I'm researching my first cruise...frustrating, but a little exciting too!