Which cruise are you taking? I believe the forum you've posted in is/was a French land tour.
However, will try to answer as best I can. Tauck ships have elevators that go between interior floors (not the sun deck) but not all go down to the Emerald deck. Cat 1 is a small room but ok for a short cruise (it's the size we had on our 1st cruise) but the windows are small so if you're at all claustrophobic you might not like.
I've also had a Cat 4 and the room itself is great for the price. More room to move around, 2 chairs to sit in when needed and a bigger bathroom than the Cat 1. It's close to the action on the ship which also means you get a bit more noise. If you're not bothered by noise it would be a better choice than the lower level cabins.