Assuming your bike is a reasonably robust/aggro HT and not an XC lightweight machine, it is do-able, yes. Both the red trails are smooth and flowy up top. Where they meet the ghetto track it gets slower and techy but then opens up at the bottom quarry section. There is also a new lower red section that looks (from what I have seen online) to be a series of big, flowing berms.
I’m not sure whether the black runs would be a whole heap of fun on a hardtail but there isn’t anything stopping you trying!
To be honest having ridden both I would say that a hardtail is better suited to Revolution than Antur Stiniog. Antur is tough enough on a full suss, even on the blue and red, and the surface/rocks are definitely more puncture prone than at Revolution.
You need to be a decent level to ride Revolution full stop, so assuming you are that, then to be honest riding a hardtail or a full suss isn’t so much about being able to cope technically rather cope physically.
What isn’t in doubt is how awesome Revolution is and they do now have a hire fleet of DH bikes if the HT really isn’t working out.
