I've been to a couple of Indian restaurants in the Nottingham area in the last couple of weeks, both of which were described as having "fashionable clientèle" - not sure that applies if the likes of me show up (OK, it's not as bad as having, say, Jeremy Clarkson walk through the door, but a balding 30-something engineer/scientist isn't going to set any fashionistas hearts aflutter).
Anyone, fashion sense of the customers isn't that much of an issue to me, as long as they're sufficiently clothed. More important (in order in which you notice it) is the appearance and comfort of seats, at which I'd give the recently refurbished Bombay Indian Brasserie in West Bridgford points over the downstairs area in 4550 Miles from Delhi, but more because the former is very good and the latter had left the toilet door to the men's open at the end of the corridor and I could smell it (fix the door, guys). Also Bombay wins out over Delhi in the comfort of the seats - definitely catering for the upmarket discerning rear here, and no cramming people in to get the money, plenty of elbow room to eat in a relaxed manner.
Food and service - no qualms for either. The following may be a little unfair on the Delhi, as the groups were of quite different sizes (five people at the Bombay, 20 at the Delhi), and catering for larger groups is always more difficult, but neither took any longer than reasonable to ask for orders and produce the food (neither were heavingly busy at the time or gapingly empty, which is my favourite level of occupancy). The food, when it arrived, was rather tasty to my not particularly discerning palate (and I'm always easily pleased by a Peshwari naan). Bombay wins on the dips again, we polished them off pretty sharpish.
Main curries, again not comparing like for like - ordered a meal I know I like from the Bombay (chicken Dupiaza), while we had the group selection from the Delhi, which naturally means more of the Anglo-pleasing creamy ones than I'd normally pick for myself. No complaints for the quality.
So, in general - I'd go to both quite happily, given sufficient time for my waistline to recover. But I'd prefer to sit upstairs in the Delhi next time.
But in short - I'd go to either again. Anyone fancy a curry?