I use a lot of 21st Century products and love the quality. Turning tools, primer pocket uniformer, arbor press, etc...All very nice quality for the money.
However, not to offend in any way, but for the price of the 3-way trimmer, I'll definitely be sticking with my old tried and true method for power trimming an prepping case mouths. I went on the 21st website thinking "I'll drop $300 on a setup like that". But I was hit hard with 'sticker shock' when I saw the price. $700 (or $500 for the conversion) to save a little bit of time on each case is really hard for me to justify.
I'm sure it's a great product tho