I have a mini & and XL and both sized pans, which I swap between the bases just for variety. I have two minis and one 16hh elderly, skinny-ish, Cushings guy, and of course, the big guy prefers the mini pan with the smaller holes. Go figure. He loves to knock them over, roll them, stand them up, etc. I fit about 2 flakes into the mini and 4-5 into the XL. The pan has to spin or else he gets peeved and eats from another hay source. I don’t soak . . . and, my guys unscrewed the caps and chewed them flat so I hope I won’t need to any time soon :). The plastic is awesome - high quality, easy to hose out & keep clean.
Side note: until they make a 1-2" pan, these are not slow feeders for minis – more like speed bumps on their way to obesity, so I will toss a 1" hay net that holds about 5 lbs into the mini feeder with the 3.5" pan and that does slow them to a normal/safe eating pace.