I own both a Toro Personal Pace and a Husky variable rear wheel drive. The Toro is 2 yrs old and the Husky is one month old. The Toro drive has worked flawlessly. My only complaint has been that things vibrate loose on it and get lost. I have to check that things stay tight.
I have actually thought about returning the Husky, because the drive wheels lock up often and unexpectedly while pulling the mower backward. The problem must be well known, because the instructions urge you to push the mower ahead slightly, with the clutch disengaged, to release the wheels. But this definitely does not avoid the problem. The problem occurs often, even when the clutch is NEVER engaged. For trimming around bushes, etc, this is very annoying and perhaps even dangerous. Surprises are uncool on lawn mower drive systems. I have had it back to the dealer once for repair - with no improvement. Why do I keep it? Otherwise it's a fine mower, and maybe I have to take some bad with the good.