Went on a dry Sunday, taking this road with some friends on the way from Shrewsbury to Barmouth, and back. As you exit Bala the roads are sweeping and quick, and then there is a wide hairpin that goes over the river which feeds lake Tryweryn. When going over this particular bend you can get the knee down with ease, but as the trees open up you are susceptible to a few gusts of wind, so I wouldn't hoon it through this bend at all.
Turning right onto the B-road you find some utterly spectacular scenery. The rugged mountains in the background loom over like an evil villain's lair, and some decently twisty roads keep you entertained. Watch out for sheep around here.
As you get closer to Ffestiniog you pass over a small creek and a lonesome house, and after this there is a cattle grid, and then it slows down A LOT. The road is narrower and visibility is decreased as you get lower into the valley. Also no road markings, so you must keep your wits about you.
The road then junctions onto the A470, which leads you into the quaint little village of Ffestiniog, and there is a pub at the end of this route for you to stop at. They seem friendly enough there, they let us use their toilets.