Over the years I have used several trimming systems ranging from cheap to expensive. None have really impressed me. Recently, after having some skepticism, I bought the Lee 3 jaw chuck and case length gauge in 375H&H. Lee is an interesting company. Some of their product are excellant 'thinking outside of the box' solutions and some are just gimicky junk.
I've only tried 3 cases so far as a test for ease of use and accuracy (I'd done a large batch of reloading a week before the Lee parts arived). This isn't enough to form a sound view. Despite my sketicism, the system does seem to work. Easy to use and all cases were within 1-2 thou. Added bonus was the ease of chamfering and deburing.
I'd like to hear the experiences of other who have used the system more extensively.
Nobody would ever use that system extensively, almost by definition. Your wrists would fall off before you got past small batch volume.
People who shoot extensively have money wrapped up into volume shooting, and that includes quality reloading equipment. Drill powered models are for folks who don't want to hand crank, but don't shoot enough to purchase a benchrest / commercial grade machine. The worst part of drill powered is the promise they fail to deliver (including quasi-drill like Trim Pro).
If you're a competitive handgun shooter, you already have something like a Dillon trimmer on your progressive press, because you're shooting 3000 rds a week. If you're a competitive rifle shooter, your likely in the 100-600 rds per week for a match rifle, and more for a action class rifle. The expectation is high volume, and still maintaining +/- .001 or better (extensively).
The drill powered units are analogous to somebody who wants a double rifle, purchases a Baikal, and tries to convince himself it is almost a H&H. They just are not, of course. As mentioned before (the OP wanted a powered unit), the Wilson is probably the best very accurate small batch benchrest quality trimmer. However, the engineering required to jump to accurate and powered trimmers is a equal jump in cost. There is no free lunch here either. It is funny how hard we work to graduate from the very best (bespoke precision), to the very worst (drill powered garbage), to quite expensive almost as good as precision volume.
Which expensive system exactly did you find wanting? What do you consider expensive?
I've yet to see the person who has gone wrong buying the Wilson once in their lifetime. And then, down the road buying a Giraud/Henderson. All I've tried this model and that model stops after that, because you realize you've already found "the one", and you just laugh at everyone else's frustrations and almost happiness.