I was there today on a Yelli Screamy, I rode a lot of the red and blue (tho no black). It’s absolutely fine on a HT, I never wished I had suspension. I did wish I had bigger tyres than my 2.25 Nobby Nics tho.
The full climb, very bottom to very top, took about 40 minutes at a gentle pace (I hate getting sweaty in waterproofs, and I was conserving energy for the descents), it’s fine, not an unpleasant ride. I did the full climb twice and some more uppy downy arsing about too.
It didn’t feel disjointed, the descents are long, interesting, and fast if you want that. Fairly intense if you go at it. Climbing back was a good chance to chill out and spin away for contrast. If you do the singletrack climb it’s interesting enough not to be a slog, tho most people did the fireroad. The ST is also much less exposed to the rain (and presumably in summer, the sun!).
Broadly: very impressed with BPW, one of my best trailcentre days, they’ve nailed it. I can’t speak for the blacks but a trailsy 29er HT was brill for the rest.