I have used both the old ones and the new stealth leeches and like them a lot. I feel they are the best at silencing the string. I never had a problem with them not holding up. They will eventually blow off, but I had my last set on for close to 6 months before coming apart. I just put the new ones on, so I' ll have to see how much better they work. I haven' t noticed a difference in sound deadening in them however.

As far as speed, the leeches wont drain your speed nearly as much as other forms of silencers.