I think this is one of the best buys I've made for loading 223, but I had one issue that I think could of been designed better and I have sent an email to Lyman/Mark 7 about this.
The hole in the trimmer die adapter is around 25,5mm. The guide on the trimmer body(motor) is 25mm and the chuck(for the end mill) is 24,8-24,9 mm. Chuck being almost as wide as the guide on the motor really makes the guide useless. If I just put the trim die adapter on the trimmer body and tighten the screws the chuck will hit the die adapter inside. So that's why only 4 stars.
For myself I ended up using a lathe and turning some more room for the chuck inside the trimmer die adapter and making ring around the guide so that the trimmer body and the adapter would have a snug fit.
Anyways trimming has been a pain in my neck for a long time and this just makes it effortless. I also highly recommend using Lyman M-die or similar afterwards since this does not deburr cases. Helps a lot when using soft bullets eg. Hornady 55gr FMJ-BT.