I have to chime in and say that BLT studios, while technically can sleep 4...you really shouldn't put 4 in them. It's really 2 adults and one kid to be comfortable. 2 adults and 2 kids will be very cramped. It's probably okay for a weekend, but I wouldn't want to be in that setup for more than 2-3 nights.
The SSR rooms have all been very recently renovated and with the fold down murphy-style bed (instead of the sleeper sofa) will make the room more usable when not being used for sleeping. It's easy to fold up the murphy bed to put it away than to fold up the sleeper sofa.
Overall, the SSR room is actually bigger and also is laid out better. I'd recommend SSR over BLT if you've got 4 people.