Concerning the fact Nap Inn is next door to White Orchid Inn I would be suspicious and at least take a look before booking. I spent few days last April in White Orchid Inn and let me just say… room is at least basic if not even characterized as hell-hole used only for short ST . So if Nap Inn caught at least some Wild Orchid Inn “style”, I would avoid it.
BR
I'd be under the same concerns myself, it's a bit of a sleazy ST soi, and i'd never dreamed of staying there before until a fellow BM recommended it.
I did go to check it out with Xyzzy last December but they were fully booked and we couldn't view a room - I guess that's a positive that it was full. The lobby/entrance was nicer and cleaner than the other places in that soi.
I would still recommend people raising their budget a few 100 bht and trying - Ibis, Top Inn, Everrich etc.. All safe bets!