I'm a very awkward bra size (32DD) and it can be difficult to find any decent bras in my size. However I've just ordered some "multiway" bras from next in 32DD and without the straps on they feel loose and on a night out I'm sure I'd be pulling them up every 10 minutes! This can't be right can it? But I've no hope of finding a 30DD 
With the straps on they feel ok but not "tight" like you would expect a new bra to feel.