What's Hot: The UniBlue PowerSuite performed flawlessly for me.
The RegistryBooster scan took a decent amount of time, as did the initial SpyEraser scan, but neither seemed to take an unreasonable amount of time.
I especially appreciated the RegistryBooster functionality. Having a product that can clean up the Registry at the click of a button can both speed up and improve the stability of your computer system.
The SpeedUpMyPC features seemed to work nicely. There were tweaks and optimizations made, and I believe I detected an increase in system performance. But, I did not scientifically measure the results so I can't say for sure that it worked, or how well.
SpyEraser also worked fine.
What's Not: 
I did not experience any issues, but reading various reviews and user comments on forums, it seems that there are a significant number of users who have reported problems.
The most common claim seems to be that the SpeedUpMyPC portion of the suite either doesn't produce any noticeable speed increase, or in some cases even slowed systems down.
Again, I did not experience any such issues, and it is possible that were user-error, or limited to specific hardware or versions of Windows. Just be aware that not everyone thinks this product rocks.