Been riding an ST 4 old + then new versions for a bit + then had an RZ 120 on prolonged test for a bit, so heres some thoughts.
The RZ 120’s suspension is much subtler + I was underwhelmed initially, but built up with the same kit that was on the ST4, there are obvious strengths + weaknesses of both.
I used the propedal a fair bit for fireroad climbing on the ST4 + although its a great technical climber, the design focus obviously was on capability on descents + singletrack. The ST4’s travel feels like it’s a longer travel bike, whereas the RZ120 feels less obvious + maybe more like a really nice LT HT, something like a Soul with a bit more cush.
In my head the RZ120 rides like a very capable efficient XC bike, that does all the xc-technical rides I’ve done on it well. The ST4 rides a very capable fun trail bike, which is much more at home on engaging rather than endurothon rides. But neither bike is an armchair ride, both make you work hard + push you into riding a bit faster. The ST4 more in terms of pumping it pushing into corners + doing the whole pro-elbows, leaning at crazy angles thing. As a Brechfa “flow” bike it felt spot-on. The RZ120 seems to nudge you into riding nearer your aerobic threshold + bung in an extra loop, just gets on with it, + still handles all the steps, drops + jumps I’ve thrown at it fine.
Anyhow opinions are like ars …e.t.c. Not sure if any of that helps.
Think the RZ 120 would do what you asked in the OP, but the forks that came with it (Recons IIRC) were bloody awful, the bike was massively better with Maxle Rebas + decent wheels.
