Scan time has largely increased in this beta 2.
With 1.6 beta 1: 2:50-3:20
With 1.6 beta 2: 4:30-6:00
Using windows xp with sp3.I tested with almost same number of temporary files and browser cache files deleted and the same number of cookies.
Scans are slower, but it is still faster then 1.5.2(from 9:00 - 11:00)