I have a DILLON 550B and XL650
the XL650 gets a lot more use.
I like them both.
XL650 for 1000 round batches of 9mm, 38/357, 40, 45ACP,
also for processing and loading 223, 308, 30-06
I use the 550B for smaller batch stuff like 44 mag, 6.8SPC, etc.
XL650
.