So the Guide descends like no 160mm bike deserves to. The rearward axle path, the lack of pedal kickback, and the ease with which the suspension moves means that ploughing through rock gardens is a joy, you never feel the rear wheel get caught up on square edge stuff. it just feels bottomless. I guess the sprung vs unsprung mass will have a fair bit to do with that too, what with the gearbox moving the weight towards the middle of the bike, It also means it corners like it's on rails.
The Highlander is similar, it feel like it has more travel than 140mm, it just feels a bit more taught, you can feel more of what's going on under you. More of a sports car than a Rolls Royce, which is exactly what i want from a trail bike, something that feels fast and responsive, rather than a magic carpet which is better on the climbs as you feel like what you are putting down is going to the trail, as being kind, climbing isn't the Guide's strong suite, you just pick a low gear and cadence, then eventually you'll get to the top. With he Highlander it feels a lot more direct. It's fair bit lighter too. My Guide is 35/36 lbs, the Highlander i rode was 31ish, like i say I'm aiming to go a chunk lower still. It still has that noticeable lack of pedal kickback too, like i said, people who say its a myth, haven't ridden a bike that genuinely doesn't have it. I think ditching the pinion for this bike is a good thing, as i explained previously, it also give people fewer reasons to not want one if you see what I mean.
As for the build quality, I was pretty impressed. Its not quite up there with the absolute best (no internal tubes for cable routing, for example), but pretty good, you can tell that thought has gone into the details, and I think what they've done with the external routing on the highlander (hiding it in a channel under the top tube) is a great middle ground they've also increase the size of the idler pulley to reduce noise an friction, though i can't say it was an issue for me on the guide. My criticisms of the Guide are that the cranks run VERY close to the swingarm, meaning any muck will rub pretty quick (i'm solving this with custom cranks, but that's not for everyone, yet) and the 135x10 rear spacing limits hub choice a bit, esp if you want a single speed hub. No such issues with the Highlander.
The company really is just two guys, Chris (the designer) and Ben (sales), Im sure you'll have read about their backgrounds. I've met Ben a coupe of times now and he's a really good guy, really keen and happy to answer any questions or concerns, while being a very handy rider. Chris is great too, Offering help in the design process of my cranks (they aren't quite ready yet) and helped as much as he could when i was fitting trigger shifters, that he's had a bit of involvement in the testing of. both guys really couldn't be more helpful.
Hope that helps, I'm really trying not to come across as a total fanboi, but its difficult when the product is this good.