Hi, recently purchased a PO 8500 and had the bracelet sized upon purchase. Store owner said it was fitted on the "looser" side and I could slide an index finger under the bracelet. It slides down to my hand if I drop my arms but it's tight enough that I can't turn the watch around my wrist one full circle (it always stays on top of wrist). Is that the proper size or should I go one size smaller? I feel it'd be more solid if it doesn't frequently slide all the way down. Would love to hear your sizes/thoughts. Thanks! As a side note, is it hard to size a PO 8500 yourself or swap bracelet/strap?? Thanks!