So I rode that Marin trail yesterday morning!
After chatting to the guys in the bike shop in Betws I decided that with the weather how it was yesterday the Marin would be the better option (they said Penmachno was somewhat exposed). I followed Simon1975’s tip of following the road along to where it crosses the Marin (it took about 15 mins there and less than 10 back).
With the weather how it was I motored round in just under 2hours as I didnt stop at all. I thought it was a good loop but the conditions did hamper my enjoyment of it somewhat.
Walked the Pyg track up and down Snowdon on Saturday, glad we did that as I wouldnt have fancied it yesterday. Was green with envy seeing all the bikers at the top and me just being up there on foot.
Anyway thanks for all the tips, it was a great weekend regardless of the weather!