Tires are all about personal preference and what you feel gives you the most confidence with the conditions you're riding in.

That said, I've tried the aggressive front/fast rear setup and really liked it. Over the years, I've gravitated to the Maxxis IKON as my go-to tire on my hardtail 29er for the trails in our area--great traction in most conditions and super fast.

Early spring/late fall, when the trails are a bit softer, I swap out for a burlier set of wheels wrapped with Maxxis Ardent 2.4s. The Ardents are more aggressive and have great traction on our area's trails.

I've not experience with any Spesh tires but I have heard/read great things about the combo you are considering.

Just know this--there are a TON of great tires on the market and you can go crazy, if you're able and willing, to find the combo that suits you best depending on your level of OCD. I think the Ground Control/Fast Trak is a great starting point!