My RCBS Manual Trim pro works well and is easy to add power via a drill attachment. However, I prefer the Frankford arsenal universal trimmer with a drill. Easy to set up and you can really do a lot quickly. If you want all in one, check out the powered Lyman Brass smith Xpress.
I've read somewhere where BR shooters blend LT30 and LT32 to make LT31. They say it works well - of course they would because they go to the trouble and risk wasting the powder are they going to say it was a bust?