My fiance and I gave one of the leather ones with snaps a try, and he seemed to really enjoy it. It made him harder and now that we've used it a few times it really seems to enhance the whole experience for him (the first time it made him orgasm VERY quickly). I haven't noticed a huge difference using it aside from enjoying his extra sensitivity. Not sure about any of the jelly or vibrating ones, but I've heard as long as it's not metal it's pretty comfortable. Good luck and have fun experimenting

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I am certain of nothing but the holiness of the heart's affections and the truth of imagination. What the imagination seizes as beauty must be truth - whether it existed before or not.
-John Keats