100% success for me, too, though I've only done it a few times. I used to train 5 days a week (20 + hrs) on gritty hard courts. Barricade/CB lasted about 1 1/2 months and vapors/2k's lasted 3-4 weeks. Lately I've been training with a new coach on clay, 2 days on indoor hard. Now vapors are lasting me well over a month, barricades over 2 months.
Wilson Blade 98S with Wilson Ripspin 17 @55