Hiya
Ive camped there in a tent, its a typical basic climbers and walkers site, no pubs or eateries within walking distance everyone seems to turn in for an early night, but ok and absolutely bang on location wise, if you were climbing Tryfan and the Glyders then you probably wouldnt need to move the van. Alternatives may be in Capel Curig itself which has a couple of pubs, the Bryn Tyrch does fairly good food, though its gotten a bit gastropubby and its pleasant watering hole there are campsites in easy walking distance.
The campsite at Nant Gwynant is good, at the base of Snowdon, fantastic views from the pass on the way down, friendly and quite sociable (its between Capel and maybe a little nearer to Beddgelert) and a great setting next to the lake, they have fire pits that you can use, think they have mains hook up too, would prob be my choice as its fairly central to all the hills but a bit more life.
Pen y pass cafe is good, they were taken over by Caban a couple of years ago for good breakfasts (food great there too!) and Petes Eats in Llanberis.
Betws y coed is about 5-6 miles away, its nice, one of my customers has a campsite there "Rynys" which has great reviews if you google it. Alpine Cafe good for food there.