Let's offroad / mountain bike / mtb / ride dirt

Help me choose a new 26er hardtail. I really like my Dialled Alpine but I could probably do with something a touch larger, and there is a strong argument that my Alpine is stronger and heavier than it needs to be for the use I give it. In many respects the best bike for me (money no object) would be a (carbon?) light as possible XC... but I'm not smooth or careful or light and would rather something a little over-engineered / heavy / steel as opposed to something that is light but might let me down. If in doubt I'd get something like my Alpine again, but is there anything else I should consider?

There's an On-One Inbred Summer Season (aka Slacker) SS in the classifieds... Light and slack enough for chunky stuff.

edit: Currenly £70 posted https://www.lfgss.com/thread121048.html
It's a bit unclear whether that frame is singlespeed or summerseason or both.