I need somone to set my expectations biscuit joinery.

I just got my dandy new PC557 (and 1000 free biscuits) last night and was
anxious to fire it up today. After giving the directions a good thorough
going over, I grabbed some 3/4" x about 15 or 16" and was gong to biscuit
join their edges - 2 #20's about 12" apart. The tool is really smooth - no
jerking or moving but still, you want to hold eveything flat and stable, or
I can see where it could try to move around a bit.

Well, dry biscuits in the slots have about a 32nd clearance, which of course
translates to the same vertical movement when the joint is together. I'd
hoped for a much more snug fit than that. You can also slide the 2 joined
edges laterally about an inch either way - but that's not a problem - you're
lining up on your original biscuit marks anyway - but the vertical movement
bugs me a bit.

After reading all the stuff here about how those biscuits swell, I thought
maybe with gluing them up, the swelling would stabilize the joint a bit. No
such luck - I even got aggravated and soaked a biscuit in a glass of water
for about 15 minutes - still loose in the slot. I just went back out to the
shop (about two hours later) and you can still slide the biscuit in and out
without problem.

Have I set my expectations too high about how snug the joint would be with
this method ?

jim