At a recent JAzz fest I had the oppertunity I had the chance to play test these two horns. I spend an approximate total of a half hour, combined with the horns. I know that is not much time, but I felt I got a desent feel for the horns. First, the MArtin, not impressice. It ws the .465 bore with revese leadpipe and it still managed to be stuffy, I dont know how. The sound was slightly darker than my bach and intonation I felt was about equivelnt to the bach with the exception of d below the staff which was almost twice as sharp as it is on my bach or callet. valve action was desent, very quiet fairly smooth. it brightened up in the upper register nicely, but I couldnt get it to really bark like I can my callet. So, on to the Leblanc sandoval reverse leadpipe. WOW! I loved this horn. very open in every register, the timbe is hard to describe it wasnt dark and it wasnt bright, but it didnt sound at all like a bach. very unique. it opened up very very nicely in the upper register and was in tune all the way to the max of my range at second g above the staff (including the one on top of the staff). intonation on the staff was very nice with the exception of 4th space e which I felt to be a tad flat and the normal d and C# below the staff. the valves were very fast, almost quicker than my fingeres but a tad noisy, not clanky like a bahc, more of a dull thud as they rose, like the top of the valve slammed into the casing. overall I really liked this horn, if I didnt already have a jazz horn Id be seriously looking into the sandoval.