So I have some alternative advice. If you think you are going to be even a a little bit interested in the hobby, don't buy anything RTR. It might seem like way too much to build a kit as your first venture but in that case, buy a used model built from a kit.

I have been in RC for about 8 years. Mostly helicopters and planes but started playing around with 4x4 trucks and buggies about 2 years ago because we built an informal track at one of my flying clubs.
First I bought a low end RTR (Tower Hobbies 4x4 Short Course Truck) which they promptly discontinued leaving a bunch of us without parts support.
Then I researched things and bought a used serpent cobra 1/8 buggy for like $300. That turned out to be a great deal.
Then I was impatient and bought another, higher-end RTR (Losi TEN-SCBE). I really like that buggy but I learned my main point about RTR vs kits.

Main point about RTR: The parts quality is always lower in RTR than in a current kit. You will learn more by building a kit and you will know how it went together when you need to fix it.

Most recently I bought and built a Losi 8ight E 4.0 and it has been amazing.

The two choices your mentioned seem very different as one is 1/10th scale SCT and the other is 1/8 Monster truck. I will say that most of the guys in my flying club buy RTR. There were a lot of Slash 4x4's and recently they have all bought 6S Talion Truggies. My answer is to going to to build a Tekno 1/8 Truggy. My Losi 8ight beats all those Talions but it is smaller and lighter so I don't like it when they crash into me. Most of Slashes are all broken after colliding with the Talions.

I looked into the 6S thing a few weeks ago. I believe it is mostly marketing hype as most guys actually racing in those classes are using 4S. True you can get insane speeds with 6S paired with a 2200kV motor but the speed is not necessarily usable on a track.

Just something to chew on....