Just stayed at Cabana Bay last week for 4 nights in a poolside suite. It was just myself and even then it was nice having a suite. If you stay in a regular room it will be like any other hotel room. Like others have said having a suite is nice but not necessary. I mean it would be nice to have a sitting area, that your child can watch tv or hang out while you get ready so you aren't in each others way, but if it does get crowded you may opt to use the money you save by not doing a suite on express which is personally what I would do.
Having stayed at HRH and RP before I was overwhelmed with Cabana. I thought it would compare to a Disney Value but if anything I would compare it to a nicer moderate. It is a huge hotel and as others have said is spread out and some rooms are far away, but if you are far from say the food court your are probably closer to volcano bay or the pools, so its a trade off. Housekeeping was sensational and always done by noon when I was there. Even though hotel was fully booked, no waits at food court, although wait to check in around 10 AM was about a 20 minute wait. The only con I thought was the transportation. Now don't get me wrong, their bus service is sensational! Never had to wait for a bus, when one was full, it was not like Disney where you would have to wait 15-20 minutes for the next one would be there right away. What I wasn't nuts about is getting off the bus, going up the stairs through security and down the longest hallway I have ever scene to the middle of citywalk and then walking to parks. Grant it this whole process takes 5-7 minutes but I much prefer walking from HRH or RP. And this is very nit picky, I would rate this hotel a 9.5 out of 10 simply based on this fact.
Now the question of express or not express, when I was there it was Columbus day weekend and the parks were very crowded in the afternoon with most rides exceeding 60 minutes. However I would get there for early entry which was at Studios or opening which was at Islands and touring efficiently could ride until at least noon with no more than a 5 minute wait. Then I would go back to hotel and nap or go to pool and then do dinner and head back to the parks. If it isn't possible for you to be at the parks that early and you find yourself getting there around 1 or 2 then express might be a necessity. But as others have said you can get the express pass there so feel it out and if you find the lines unbearable then get it.