I have both the Lee & the Possum Hollow for .223 & they both seem like good tools that do what they're supposed to. Both are pretty much foolproof & will only cut as deep as they're set.
The PH is much faster. For that one, you chuck it in your drill and the cutter head spins. The Lee trimmer is backwards (from a speed standpoint). For it, you put the chuck in the drill and then chuck/remove each piece of brass. You spend as much time changing pieces of brass as you do cutting.
But then to chamfer & deburr, it's faster with the case chucked in the drill. Using either the Lee or the RCBS tool, you just kiss each end to the spinning mouth & it's done. With the PH, you need spinning chamfer/deburr tools as well since the case isn't spinning.
Of course if you're only doing a few at a time it's no big deal. Large batches & my hands really start to hurt doing the chamfer/deburr ops by hand.
They each use a different datum. The Lee uses the base of the holder so it's going to give you a the same OAL from base to mouth every time. The PH uses the shoulder as a datum and will give you the same neck length every time. Which is better/preferable, I have no idea.
What I've noticed as far as overall finished length is that the Lee seems to hold +.002/-.0005 and the PH seems to be +/-.0025 so there is more variation in overall length from the PH. If that has any significance I don't know either.
As far as cutting, the PH cuts much cleaner and isn't as sensitive to tool pressure. The Lee will slightly open up the mouth if too much pressure is applied. They both clean up the same after chamfer/deburr, but there's less chatter & a cleaner cut with the PH. This could be my technique & not the tool's fault. The PH is heavier so it spins a little slower so I might need to slow down the lighter Lee cutter to get a cleaner cut. It's not bad and neither needs noticeably more/less effort to clean up.
They both need the chips cleaned out frequently - about every 10 cases or so depending on how much cutting there is. That's to be expected. To look at them you'd think the Lee would need cleaned out less because the PH has everything captured, but in use the PH does a good job of throwing its chips out of the hole. The Lee's chips build up and get caught. Just a couple quick taps on a hard surface cleans out either one.
Lastly, I did a very Bubba setup to use the PH cutter and still have a quick chamfer & deburr. The RCBS tool can be chucked by the deburr end (barely) so I have a spinning chamfer tool. The Lee chamfer/deburr tool can't be chucked (in any drill I have) so I used an old #2 size screwdriver bit ground and pressure fit through the slot on the nose. I put a little epoxy there to keep it in place. So I can mount 3 drills in a row, have them all spinning, and hold a case and go from cut, to chamfer, to deburr very fast. It's a little quicker than chucking in piece into/out of the Lee case holder.
Yes this is VERY BUBBA - it works