this forum-thread might be of interest for you:26"/Stahl/Rennlenker (Ausrüstung Reiserad)
Yoon (Simon) here says that the shown combination fits (even with the drop bars), because of his particular physical proportions (long torso). I own the M1 with a flat bar, and I
can´t imagine how this could fit with drop bars (but everybody is different....)- although I generally prefer these kind of handlebars. I am not shure if it would be wise to take a smaller frame and/or a short stem, because this might affect the riding quality.
Simons main reservations (that is why he was looking for a new frame) was the poor coating and the horizontal drop outs which appeared to be inconvenient for him.
In my estimation the stability of the M1 is really good, but this certainly depends on the particular conditions (weight, road conditions etc.) you plan to use the bike.
I think there is no big difference in stability between the M1 and the Surly LHT (which I testet once). So my advice (from the distance) is to take the Surly frame into consideration, especially if your physical proportions are "normal"
(perhaps the $ will drop further...)