Reserve BMQ, both part-time on weekends and full-time in the summer, are the exact same. You learn the same stuff. Granted, you may have to travel a while to use the gas hut and the range on a part-time course, because you aren't in a Camp/Base, but that's about it.
On my full-time BMQ we did not do a swim test. However, when I got back to my unit we all went to the pool and did it because we were going on an exercise where we were using boats.
If you're trying to debate between doing the part-time BMQ (which are all starting soon) versus waiting for the summer for the full-time, do the part-time and get it out of the way. Trust me, yah ain't missing much doing full time. It just means you're away from home for a whole month instead of a whole weekend (except not even a full weekend). This way, you can do your SQ and DP1 in the summer and be a fully trained Pte when you go back to your unit.
The swim test, if that is what you're worried about, really isnt' that bad. What I found the hardest was the fact that you have your combats on (no boots though!). Those things weigh you down a lot more than you'd expect.