Here is a few pics I took between my Sig P320SC and the new HK P30SK.
Build quality both feel top shelf. They are almost identical in size except the P30SK is bit fatter. The P320SC holds 12+1 9mm and the P30SK holds 10+1 9mm. Trigger on the P320SC is noticeably lighter and the reset is shorter than the P30SK LEM. Barrel length is 3.6" for the P320SC and 3.27" for the P30SK.