I have stayed in both the CR and BLT. BLT studios are indeed smaller than the rooms at the CR and as mentioned, only sleep 4 where the CR rooms can hold 5.
The difference, however, is that the BLT 1 bedrooms are not that much more in price than some of the tower CR rooms and comparing those, BLT wins hands down.
For example, in the first few weeks of July, you can get a LV 1 bedroom at BLT for $580 (rack rate) and its $525 to $550 for a MK view tower room.
We consider BLT as part of the same resort as CR so there is no difference for us in terms of convenience as we have stayed in the tower and garden wings as well as 3 times at BLT and I found the ease to the main building in terms of food, shopping, and monorail to be similar. Matter of fact, my stay in the garden wing of the CR put me farther from things than any of my BLT stays so far.
One of the reasons we bought in to
DVC when they built BLT was the ability to stay at our favorite location but upgrade the size of what we were staying in. We are a family of 5 and the thought of having more room for no more than what we were paying (and over the long haul, really less!) was what pushed us in to becoming members.
Now that 2 of my 3 children are college age, we are down to traveling most of the time with only 3 but after staying in the 1 bedroom last year, I would never go back to just a studio unless it is DH and I only. And, even then, it would be only for those short weekend trips, not our yearly summer ones.
Now, I have stayed at BLT in a studio with 4 (me and the kids--all who were teens at the time). And, while it is tight and wouldn't recommend it for an extended stay, it is doable if you fold up the couch each morning and don't plan on spending tons of time in the room.