As much as I love the V8, if I were buying a Genesis today I'd get the sport. We all know that the V8 doesn't get interesting until ~3200rpm or so; it would be nice to have something which had a bit more low-end punch.
The reviewer and I are in agreement about the vague back end of my 2015 3.8 and the G80 Sport I test drove. It's just too vague, but it can be made better with the right tires. And, of course, lose the sunfoof or moontoof.