Vibrating penis sleeves - do they lessen the pleasure of the man?

Forum highlights on Masturbator sleeves:

Sleeve / Masterbator Lube
What type of maintenance, and lube usage has been proven to be best at preventing the all-too-common cracking, ripping and tearing associated with...

Textured Sleeve Length?
So, there are six reviews of this thing floating around here at Eden. The sizes provided range from two to five and a half inches. The description...

masturbation sleeves vs pocket pussies?
What are the major differences between a sleeve and a pocket pussy?

#AskEden - Fleshlight Sleeves available for purchase?
Dear Eden, My boyfriend loves his fleshlight. And I mean LOVES it. I would love if you guys started carrying the different sleeves for individual..

Which sleeve has the best feel?
Which sleeve gives the best feel to it?