My two cents' worth...
Apart from the fact I needed a heavier-duty frame (Sherpa in my case), the real advantage of 26" wheels for me is the greater strength made possible by their smaller diameter and the larger selection of tires in a variety of wider widths. You can readily source 26" tires from roughly 32mm to 50+...and have them fit within the forks and stays. Furthermore, the smaller wheels virtually eliminate the possibility of toe-fender overlap, a very important characteristic for me, as I tend to snake up 24% grades in low gear with a lot of front-wheel movement as I slog along antelope trails fully loaded. Your needs might be different, of course.
As a roadie, the "look" struck me as a bit strange and ungainly at first, but I have adjusted and now my 700c-wheeled road bikes look spindly and ungainly in comparison.
Previous to the Sherpa, my only experience with 26" wheels has been on my Burley Rock 'n' Roll road tandem (converted to road orientation with drop 'bars). Holding constant for tires of similar construction, I do believe 700C and 26" roll comparably on smooth surfaces. I also believe the smaller overall diameter of the 26" tend to fall into gaps and potholes that are more easily bridged by the larger 700C tires, but...! The 26-inchers have fatter tires and can be run at lower pressures and still roll efficiently while providing a lot more cushion and comfort for the rider, so it is probably a wash overall on poor surfaces as well, with the edge going to to the fatter-tired 26-inchers. I am one of those people who always used a road bike off-road (non-competitive cyclocross, fire trails, loaded touring, pretty much anything). It was hard at times, but built a good skillset. That all changed when I took the Sherpa to some of the same places. Equipped with 26x2.0 Schwalbe Duremes instead of 700x32C Bontrager Select Ks, it felt as if I could do the rides with my eyes closed -- it was just so easy. Much, much easier. I suppose the best of all worlds would be a twenty-niner (frame built to accept fat, 700C tires), but as it is, the 26-inch wheels seem the ideal for me overall.
My two favorite bikes are each set up as all-rounders, one is a tourer with 700x32C (akin to the Club Tour in spec) and the other my new Sherpa with 26"x2.0. I think they fill essentially the same overall niche, but one (Sherpa) definitely excels at the heavy end of the spectrum, whereas the other does not. Lots of overlap in the middle of their respective ranges, especially for day rides, commutes, and when carrying reasonable loads. For rough roads and heavy loads, the Sherpa wins it all.
And, for what it is worth equipment-wise, I am pleased with budget Deore on the Sherpa. Compared to the 30 year-old friction stuff and 22 year-old indexed Deore I was used to, it is another world in terms of high function and design. For me, it has been a tremendous value, presenting much of the functional performance of Shimano's higher-level kit while freeing up monetary resources for other things like onboard charging systems, the GPS, and a fresh set of panniers. Deore also gave me steel inner and middle chainrings, which I expect to be an advantage in providing long wear and lower replacement costs given the gritty desert sands of my Great Basin tours. While plain ol' Deore isn't on your list, I believe you'll find Shimano's lesser offerings still offer high function for great value. As for the top-line stuff...there is indeed a positive difference in weight, feel, and function, but only incrementally, given the higher cost.
Does that help? Hope so...
Best,
Dan.
