Nigeyy

Where to start?

Well, I tour with a bike with disc brakes (Avid road BB7s), with a frame and fork that has specific disc brake mounts (Dawes Sardar, old steel style).

Advantages: better braking modulation, better performance in the wet, no rim warping issues
Disadvantages: usually need disc specific racks, more expensive (need disc hubs as well as the brakes!), relatively more complex, less likely to find parts in far flung places

What it all comes down to is a personal choice: I love mine. However, unless you have enough money and just really want them, I'd recommend sticking with traditional brakes -the difference between performance of good quality discs versus good quality traditional brakes is just not worth the price cost IMHO. Touring has been done with traditional brakes for many years quite adequately. Whether or not you are prepared to pay for that improvement (that you could argue might not be needed anyway!) and its associated disadvantages is another matter. However, since I've paid already, I'll never be taking them off and I do find them to be an improvement.

FWIW, I do find some "anti-disc" arguments to be questionable, namely the old chestnut that they are more complex and less reliable. I've never had a disc fail for touring nor mtbing (arguably a different but certainly tough environment) and I still use "complex" derailleur gears. The argument that you may not be able to fix a broken disc brake also doesn't wash with me -to me the same argument can be made of traditional brakes (if the arm brakes, what are you going to do? That's certainly not fixable!). There might be some merit to the fact you may not want to use disc brakes for touring outer Mongolia, but even then, carrying a spare calipre with pads and disc may well be more than adequate and even overkill. I say "might" because I'm not touring far out places, so again discs are more than suitable for me.