I would not use anything from Piriform after it transformed to Avast property IMHO
I use Wisecare 365 Pro, I am not saying it is right, it just the way I chose to go.
Just, stay away from registry cleaners IMO... The registry isn't really all that big to begin with and obsolete entries don't really hurt performance like many would think.
I have used both CCLeaner and BleachBit for the past three years on my XP Pro rig without problem, so both will be continued when I transition to Win 7 Pro & MX Linux. No matter which I run first, the latter finds stuff the former missed. Neither works that good on the Firefox cache, but Firefox will not survive the transition, so it don't much matter.