6 of us did it last September. It's pretty tough, although if you're used to all-day riding, then you'll be fine.
Navigation is far from simple. We had three GPS'd bikes and lots of maps (OS and IMBA versions), and still needed to check every now and then to make sure we hadn't gone wrong. Way-marked trail centre it is not.
We stayed in The Crown Inn (I think) on the first evening. Nice pub with good beer & decent food – nothing special. They locked the bikes away for us, but the rooms were a bit rubbish. It did the job, but if I was going back I'd stay somewhere else in town (possibly The Elan hotel) and head to the Crown for evening drink.
Second evening was at the Black Lion in Llangurig – it's an old skool B&B (not the most friendly welcome I've ever had, but they served us beer & food and it was warm, dry & comfortable) and they stashed the bikes for us. Top tip for brekkie is to say you're a veggie 'cos then they'll give you a decent portion of beans on toast, preferable to the traditional fry-up IMO.