Bit the bullet and recently purchased the swage it 550, and also learned some important info on these tools.
I can't go into full detail because I have mutual respect for the source, and also because this is a heated lawsuit topic (I believe with active NDAs), but basically the complaint of parts breaking had nothing, ZERO, to do with the ram, or the shellplate, or anything pertaining to the ram. Apparently the part that was breaking was only on the 650, and was caused because Dillon took a short cut in the manufacturing process. The added upstroke force exposed this flaw and the part broke. Dillon did not want to admit to designing an inferior product so they refused warranty on the swage it instead. My understanding is the flaw was not evident on the 550, and the redesign to correct the flaw on the 650 was integrated into the 750.
As far as the tool, it brought my prep time for 2000 casings from maybe 3 days to 6 hours with small breaks in between. Once it's set up right it's shockingly fast. Having size/decap, swage, and trim on the press and completed in one stroke brings the loadtime near pistol levels. Can't complain with that.
My only complaint with it would be there isn't really a way of positive swage verification. Some of the cases have the satisfying "thump", but the cases that are not primer crimped do not, meaning there is a tendency to really go down on the swage if the "thump" isn't heard on non-crimped cases. But because there is the possibility of over swaging (can bell the rim of the primer pocket if the tool is pressed in too much), this also causes the tendency to not swage crimped cases. I eventually was able to rationalize with this by eyeballing the caseheads as they were lowered into the swage -- if they only lowered slightly, add pressure; if they lower 1/16", don't add pressure.
So if I had any input for improvement I would say some measure of positive verification would be nice. I didn't have too much trouble with seating primers, nothing outside of normal anyway. I could fix that with a chamfur, but then again why screw up a good thing? I've basically retrofitted a small bullet factory into my office.