I started with a M17. Bought a P320C RX. Swapped out the grip and the slide. Sold the "P320 compact" as a full size p320 FDE slide and grip. Swapped the Compact RX slide, greyguns trigger, and fitted a Holosun 507c, found a x-carry compact grip and love my "M17" now. Now I like it more than my STI staccato...well I feel less guilty abusing it