Are you keeping the 78mm ski? If so, you'll love the S6 as a compliment to it. Great choice (stop reading now). If not and you want the S6 to be your only ski:
The S7 has camber and a super short turn radius, it's a completely different ski (not to mention trying a ski for a day is WAY different from owning it. It's like a one night stand vs marriage, flaws just don't matter much 'in the moment'). As I said, I'll bet you will love the S6 in Utah, but as a ski you can "use for the groomers I ski and the powder/ mixed conditions I find in Utah" combined with "I do not do bumps" well, the S6 will be great for powder and some mixed conditions, but jumping from 78mm to a reverse camber ski that is 110mm is pretty extreme and pretty much a niche ski for even 'locals'. Skis like the S6 are really, really fun and can do more than just float in powder... but they aren't all-around skis as some like to claim. You can ski anything on anything if you have the skill set, but there is a such thing as 'right tool for the job'. A pair of vice grips can solve a lot of problems, a plunger does one thing well... the S6 is a plunger.
I'm not sure why you bought these skis then asked this question. You asked for insight from someone that has skied them, I have and I like them but I wouldn't own them if I had your situation, I'm sorry to say that but it's what I think. I'd own something like a Kastle BMX88 or 98, Blizzard Bonafide, Rossi S3, Nordica Soul Rider... something between 88mm and 105mm, looking to be at the new 'all-mountain standard' of 98mm, probably with slight rocker. You don't live in Utah, you visit... there is a difference.You do not ski bumps, that will really limit the amount of soft snow you ski while on vacation if the stars don't align for you.