I've always been a huge Menzerna fan, but the stuff is so expensive, I've been using High Temp and Optimum lines of polishes alot more lately.
I really like the Optimum line for light correction work. On hard clears, you'll need to go one step more aggressive on your pad choice than what you would normally use, and it'll take a bit more work to get the job done.
I don't particularly like Optimum Polish as a finishing polish, though. It just doesn't work as fast, not does it give as good of results, (IMHO) as Menzerna PO106FF. Even though the stuff is crazy expensive, I think PO106FF is really worth the expense.
The Optimum line is sooo much easier to use than Menzerna Super Intensive Polish. Lately I've been saving the SIP for use only on really hard clears, and doing most of my correction with Optimum or High Temp polishes. I really like the long working time of the Optimum, and as I said, they are sooo easy to use. High Temp Extreme Cut does have more cut than Optimum, but the High Temp has a (to me, at least) very short working time. I'm able to finish the Optimum Compound or Optimum Hyper Compound out much better with their longer working time than the HTEC.
If you're new to the rotary, I'd definitely go with the Optimum line for correction, and PO106FF for finishing.