Can someone explain these, as the website doesn’t make it that obvious what the actual differences are.

The Switchback is the slackest and most downhill orientated. The sherpa is the most cross country orientated, and the slackline is somewhere in the middle.

Saying that though, the Sherpa is pretty decent on the fun stuff as well by all accounts, and the Switchback can climb.

I believe they have a little graph on their website showing which bike model is suited to which type of riding the most.

Slackline is a trail bike. It’s the Stanton equivalent of a cotic soul. So 67ish headtube. 853 tubeset. 120-140 fork.
Switchback is more like the Bfe. 65 headtube. Super short chainstays. 631 tubeset. Thicker gauge tubes, burliest dropouts etc. You won’t break it. 140-160 fork.
Sherpa is a 29er slackline. 100-120 fork. 853 tubeset. 67 headtube. Stupid wheels 🙂
All well regarded. I’ve got a switchback mk1 and it’s great. Super tough, very playful yet doesn’t feel out of place doing a 30 mile xc ride either.