Is there anything out there significantly better than my 5 yr old Anthem with RLC100’s for a bit of XC racing and the odd longer race? It rides pretty well still and don’t know if it is worth changing it.

If you believe the marketers…

something with 29″ wheels…or maybe 650b…no definitely 29…

The whippet has to be the best non bank-breaking XC race bike. No idea if it’s better than your anthem – probably not tbh, but it’s a good ride and unbeatable value.
It also looks better than your anthem – it’s not often you can say that about an on-one bike.

take a look at the On One 29ers as they have been selling some frame off. Or the Canyon 29ers.

Anthem x 29er

cynic is right. The short answer is no. bike companies have only started to try to sell 29ers because there isnt any new radical tech like disc brakes or full sus to be able to hype it up. you can only redesign the suspension so many times to make it better before its then not that noticeable when they improve it