How reliable is "Try & Decide"?

I tried this feature only once... when I decided to back out my installed software, I felt my system was not back to the old stage as it was before I started the try process. So now I am skittish about using this... Thats why I wanted the set restore and recover of Win 7. But even that is not that reliable.. often times, when I try to recover from a previous restore point it comes back and says,,"unable".

I do Flight simming and I constantly install addon software... and sometimes these give me grief and I have to go back to the previous state. Recently it was some of these add on installs that got me into trouble that I had to do a disk image recovery. This is often ok if I have just one HD or SSD.

I have like 5 HD/SSDs (each one average 1TB-2TBs) and sometimes an Install is spread across multiple HD/SSD although the number and file sizes are small... But since the number of files in the system for simming run into the 1000s, finding the new small set off installed files, are like searching for a needle in a haystack,. Because of this nature I prefer something like "Try and decide" or "Set restore Point and restore.

So I really want o use this "Try and decide" feature...but I need to have confidence in it.