Trans Wales MTB Ride - Any must include sections?

Having recently completed the Coast to Coast off road me & the misses are looking to plan our next off road cycle tour but this time we want to slow it down, and take in various bits & bobs along the way. So we're thinking about getting the train up to Bangor and then riding back to my place in Bristol over the course of two weeks, given the record for riding from Bangor to Cardiff is less than 24 hours, we reckon two weeks should be fairly relaxed.

So far our route is as follows:

Day 1 Train to Bangor then ride to Llanberis
Day 2 Have too much for Breakfast at Pete's Eats and ride Snowdon
Day 3 Ride to Coed y Brenin
Day 4 Play on the trails at Coed y Brenin / Take it easy / Sleep
Day 5 Ride to Machynlleth
Day 6 Play on the Mach trails / Take it easy / Sleep
Day 7 Ride to Nant yr Arian taking in some of the Syfydrin Trail
Day 8 Play on the Nant trails / Take it easy / Sleep
Day 9 Ride to Rhayader possibly via the Elan Valley
Day 10 Relax with friends in Rhayader
Day 11 Ride to Llandovery (I believe that there's couple of trail centres on route
Day 12 Relax with friends in Llandovery
Day 13 Ride around the Breacon Beacons
Day 14 Ride to Abbergavenny
Day 15 Ride to St Briavels via Monmouth and the Forest of Dean
Day 16 Ride home and have a wash before returning to work

Now can anyone recommend any amazing pieces of trail on route which we have to ride? or any night mares which we need to avoid?

Thought I'd give this a bump, are we all quiet because we're jealous...?