Soz to resurrect a thread, but this is the same dilemma I was faced with a few days ago..
though I was silly and did both (yesterday) – silly because I'm not at all fit 🙁
Consequently I took almost 2.5 hours to do Cli-machx (I got lost, which resulted in tears of frustration and a lot of extra climbing) and was completely underwhelmed by the descent. (I'm not very good so I had to walk parts of it, which I don't mind, but it was odd seeing as the rest of the singletrack had been so simple)
And because I was knacked from all the climbing, I took the whole 3 hours to do MBR.. I must say the first half of it is awesome fun. but then there's just lots and lots of climbing up fire roads. and again, I felt the final descents just weren't worth it. (for a beginner anyway. I'm guessing if you're a local etc. they'll be much more fun)
I know I'm leaving myself open for ridicule but I accept fault for doing the two in the one day when I have such a low level of fitness to begin with!
And where were all the jumps and big swooping berms?
I had planned to do Llandegla as well as a nice 'warm down' and then decided I was too tired and sore to attempt it today.. So I have an excuse to go back to Wales (lovely place) later at some point 🙂