I’ve taken a few road trips to Llandegla for a ride, it’s about 4 hours each way for me, it’s not the worst thing in the world ever.
As for Brechfa, I think it’s brilliant. The Red and the Blue are great – as above don’t discount the Green because it’s green, it’s epic fun – but the blue includes all the green so if you’ve got the legs left after the red I’d do the blue.
I personally don’t like the Raven / Black, it’s got some nice sections, but they’re tied together with a lot of featureless miles for the sake of making it long IMO.
A few tips, there are two carparks – The one for the red is a few miles up the road from the one for the other trails.
Whilst they’re trail centre type trails, it’s not a trail centre, facilities are limited to a car park and a couple of portable toilets, so don’t expect to be able to shower etc before you head home.
You’ll want some grub after riding, ‘The Shed’ is very nice, it’s tucked away down a farm track in the car park for the Green/Blue/Black trails they close over Winter but they should be open in March, if you want a pint, the Black Lion just outside the other car park is lovely, food is typical pub food, but it has a lovely beer garden over looking a old stone bridge over a river.
Also, Cwm Rhaeadr is only about 20 mins up the road, it’s a short little trail, but good fun and technical in parts – depending on your legs I’d personally ride Red, then Blue then Cwm Rhaeadr and then head home, there’s loads of videos on YouTube of them all if you want a gander before deciding.