I’ve done the HONC 50 twice, with my GF. It’s really a CX event so not techy stuff any basically capable off road rider can enjoy it if they are reasonably fit. It has a nice vibe. The mass start is a bit silly but fun except for the “elites” who start too far back in the mob “coming through!”. I usually start about 3/4 back and slowly pick my forward over the ride.
My first year is was hail, rain and mud. The second the dry, hard-packed and t-shirts.
Worth putting fast-rolling tyres on.