What I find incredibly nice about Stainless steel reels is that if you clean them in hot enough water, most of the water will evaporate from the heat that transferred to the reels. If the reels happen to be a little bit damp it doesn't matter anyway, so if I have a lot of film to process I have enough of them by owning two sets. Load one set while I process the other... Easy peasy.
For me this is a huge advantage, because about 70% of the year my darkroom is in a fairly high humidity basement. Plastic reels simply don't work for me unless I happen to be processing film during the four months it's actually dry in there.