saph, everyone has some cogent points above, but there really is no reason to not do it if you're happy with how the bike treats you on tour. The efficency, the heel clearance ,the mileage, all valid concerns, so it depends on how you feel about it....
I did my first mountain bike tour 19 or 20 years ago and it was as enjoyable then as it is today.
notice quite a few euro 'tour' bikes are 26" wheels and the like. no biggie.