You must be thinking of the Lee system. It is a good and inexpensive system.
Most other systems use a small lathe type of tool. There are several minor and a few major variations, most of which revolve around how the case is held in place.
There is always some system of adjustment, unlike the Lee which is fixed at a predetermined length. Most of these other systems allow you to choose the actual length you set the adjustment to.
It would be best for you to go on various loading equipment companies web sights to see their advantages over the competition.
I currently use a L.E. Wilson case trimmer, which is quite different in principle than most others. I also use two sizes of Forrester trimmers (they are small lathe type units). I have owned and used 2 types of Hornady, 3 different RCBS, and borrowed a Redding as well as the old system of "Trim Dies". I sold off all of them as I found things I couldn't accept.
Some of the lathe base systems have additional functions like case neck reaming, case neck turning, and various primer pocket functions.
The only problems I have found with the Lee system is in production speed and inflexibility (some chambers were cut short and require shorter cases by a few thousandths of an inch) and availability of really unusual case lengths.
Have fun researching and discovering why you want and don't want various products.
Ivan