If you decide to order pins, my favorites are the modified Dritz pins that Green Mountain Diapers sells--same sort of thing you'll find in a fabric store, but even a little sharper. Another thing to consider is these, which I just ordered a half-dozen of and will be mini-reviewing shortly. They're like a cross between a Snappi and pins. I could never get a snug, trim fit with a single Snappi, but I expect two Boingos (one on each side) should be perfect. Can't wait! Anyway, enjoy the prefold adventure! The feeling is definitely nothing like a disposable or the training pants; you will be waddling for sure!
I see. So, first off: No prefold is going to be as soft as those training pants, so don't expect that. The prefold fabric--not just Baby Pants', but everybody's--is tougher stuff, made with heavier thread, etc. That said, the twill fabric definitely wins for softness over the birdseye. Absorbency? I'm not sure; they've both performed similarly on me. Ease of use? Well, the twill is a bit harder to pin. I'd definitely advise you to steer clear of the large (and rather blunt) AB/DL pins that Baby Pants sells and get some baby diaper pins from your nearest fabric store. One final point on softness: The usual recommendation is to avoid fabric softener with cloth diapers, as it does reduce absorbency. My recommendation, if you really want softness, is to experiment. It's easy to undo the effects if you don't like them. I like them--softness, scent, and the pins just glide through. Try without softener first, however.