I've done something over 150 miles on a demo bike this week (Standard mod mechanical DA, Knot wheels, Vision bar) and I'm pretty impressed. There's some stuff it does well, some stuff it does exceptionally well, and a couple of niggles that would be easy enough to change.
First, it's stiff. Solid in the BB and headtube so climbing out of the saddle actually feels lively enough despite the weight. Picked up a KOM on a 150ft rise for what it's worth, and some generally decent results on longer gradients. Next, it's quiet. Both from cables etc but also wind noise. I'll need to pay attention when I'm back on my own bike tomorrow but the frame and wheels don't seem to make any discernable wind noise at high speed. Not a very scientific aero test but hopefully a good sign
What it does brilliantly is corner and sprint. I don't remember being on a bike that gives as much instant confidence to carry speed through corners. It's not as exciting as my R5, but for fast entry, fast exit and mid corner stability it is so, so good. I went and checked the geo and it is quite similar to the Evo but with a slightly longer FC and fractionally different rake/trail which makes sense for the stability, and the chunky headtube gives the steering precision I expected from it. The rest of it though is how good it is at deadening road buzz. Maybe it's the Save stays, maybe it's just the frame weight and wall thickness but it stays planted on the tarmac even when the road surface sucks. It's the same for sprinting, it's incredibly planted at max effort. So much so I intentionally rode the 'crap line' at one of our local group ride sprint points, where the cracks in the road normally buck the bike and suck speed from you, and it was pretty much a non event. Wasn't comfortable, but the back wheel kept traction all the time and the power kept going into the road.
I'm not a fan of the handlebar - it seems like the cable routing of the Vision bar (exits right at the back) is the worst match for the SystemSix for getting the hydro cables cleanly through the guide and into the frame. It's not difficult to route, just seems like a bar with a routing hole underneath and further forwards would leave you with much less visible brake hose. It also seem to have too narrow a centre section to fit a K-Edge out front mount. Maybe Damon knows of a good option for a mount? In contrast the Knot bar on the HM has very clean routing in practice, and a solid, aluminium Garmin mount. Total opposite of the plastic bit of crap on the new Propel
(The HM we have is too big for me, but a Cat1 colleague has ridden both and says it's noticeably more responsive). Lastly for now, the Prologo bartape sucks but the Dimension saddle is very good - YMMV!
Couple of photos, including proof that I tried it out on some decent climbs.