I would take the spotter. If I can glass up some animals across the canyon and get a better idea of where I need to be the next morning or maybe even that evening, I’d like to be able to do that.
As others have said, it depends on the country I'm hunting. If it's broken country or I'm high up on the mountain I glass often and it's typically with 10×42s, sometimes on a lightweight tripod. Mobile but not trophy elk hunting here. If I'm spiking out overnight (archery or early muzzleloader) no freaking way I'm huffing an "anchor weight" 65mm/85mm up and down the mountains unless a hunting buddy wants to carry it. Otherwise, the spotter stays in the truck.
Typically, most of my spotter/tripod glassing is done late afternoon/evenings from known or pre-selected vantage "waypoints" to locate elk and set up the following day's hunt. Usually, I'm truck camping/day hunting.
There seems to be a lot of people saying you don't need it because of all the dark timber. I am still planning on taking mine since there are a few ridges I can get to and glass into different bowls.