Originally Posted by chaadster

Yes, as Clifton noted above, but additionally the other equipment spec (e.g. seat, handlebars), your position on the bike in terms of comfort and control, and handling characteristics (such as derived from a longer wheelbase, or more stable steering).

The gruppo merely changes the gears, and while some offer crisper shifting, or more amenable controls (e.g. Gripshift vs. trigger shift types), greater longevity or lighter weight, all that is easily changeable. You can swap chainrings, rear cogsets, shifters and derailleurs. A poorly fitting frame, on the other hand, or a bike that simply doesn't feel right because it's too short or whatever, is a more durable problem.