I have a LNL AP setup for 45ACP with the same setup, MRBulletfeeder die with my homemade bullet collator and I'm also very happy with it. The only problems I have are related to the bullet lube that gums the feeder die but I know that I would have the same problem regardless of the press.
I also have a 550 that I really like and enjoy. I feel like both presses have their advantages. For me the LNL is very good if I leave it for .45ACP as it would be a PITA for me to swap calibers and it would be the same for me with a 650 (I know that I could swap the toolhead that also has the powder measure but I would also have to adjust the case feeder, primer system for small /large pistol, etc). In a nutshell, the more automated the press the more I like them to be dedicated to a single caliber.
On the other hand, for me the 550 is the easiest to swap calibers and it's rock solid in terms of reliability. However it's slower and the lack of auto indexing might be a bummer for some (either for speed or the possibility of a double charge).