Never used the L33 Versa (well maybe on a rental but memory is foggy on it).
Your L70 Versa I used extensively and it is a great little putter, IMO.
If you do change I would say consider sticking with the same scale. I bought the wrong one by accident but stuck with it as soon got used to the new scale - Scale is the last thing I care about, just personally.
I would say the roll out is an inch more controllable some of the time from distance, but with any half decent ADTP the L70 is long since very fine.
If you just fancy a new toy then great. If you are looking for something to noticeably improve your game the new putter is not it.