So the Giant 2018 Trance 3 Listed for $2350 and has some noteable differences over and above the HH1. While the Drivetrain is Shimano Deore 1x10 which is essentially the same as the HH1 and the Brakes are the same too, the Giant comes with a dropper and a slightly higher spec suspension. Also better wheels/tires and it is setup tubeless from the factory. In addition to the slightly better shock, fork, and suspension geometry (Maestro) the Giant has more travel in the suspension - 140mm rear vs 110mm on the Hawk Hill. The Giant fork is 150mm vs 120mm for the Hawk Hill.
More travel isn't necessarily better, it depends on what you are planning to do with the bike - what sort of terrain your riding. As a first FS MTB, either one will be great fun. Both are good for trail riding although the Giant might be a little better for more rugged terrain, drops, jumps, etc., the Hawk Hill can do pretty much the same thing.
Here in FL most of our trails are flat with some man-made "hills" and lots of obstacles like rock piles, roots, jumps, etc. I actually prefer a 120mm to 135mm suspension for the stuff that I encounter here. I demoed a couple of full-on Enduro style bikes a few months back (170mm-180mm travel) and frankly they were just too much for my style of riding. I also demoed a couple of Cross Country race style bikes (60mm-80mm travel) and although they rode great and were super light, I used up all of the travel on them pretty easily. For me, the 120mm-140mm range is the sweet spot.
So, given your choice, I'd probably go for the Giant as it is a very compelling deal (over 35% off). The Hawk Hill is full list price ($1599.)
Which color is the Giant - Green/Black or Charcoal/Neon? Where do you ride?
https://www.giant-bicycles.com/us/trance-3-2018
https://www.marinbikes.com/bikes/201....5-hawk-hill-1