I said in another thread that this whole hobby is a matter of trade-offs. I think John Armstrong used the phrase, "Givens & Druthers." For the sake of ths discussion, "givens" refers to fixed things that aren't easily changed... walls, doorways, etc. "Druthers" are our ideal circumstances; curve radius, aisle widths and turnout sizes, for example. From there, one simply decides how much they can bend based on the physical circumstances.
Having said that... I had a switching layout that actually used 15" radius track. I ran small locos and nothing any longer than 40' on it. The few problems that I had were simply equipment related instead of trackwork. So, I think that one could cut back to 26" or even 24" and still not have an adverse affect on performance provided that your equipment is up to snuff. Again with the raised trackwork, the sharpness of the curves would be minimized from the viewing angle.
So, to answer the question, yes, I feel that I could have gotten more track in the given space AND wider aisles without affecting the overall layout performance. Both wider aisles and more track would have been desireable in hindsight.
dlm