Ease of servicing disc vs. rim brakes How easy is it to keep a mechanical (non-hydraulic) disc brake system working at home with a set of "normal" (not bike-specific) tools, especially compared to rim brakes?

Discs seem to be currently en vogue in adventure biking (cf. the Salsa Vaya) and even in cyclocross bikes (cf. the Merida Cyclo Cross 300). Despite their all-weather stopping power, I have heard several people (even people working at LBSs) say that they are a lot of work to adjust. How true are these claims?

Can a layperson reasonably expect to keep them working optimally without the help of a LBS, or do they entail regular professional "servicing"?
There's two different situations here.

The first time disks are set up after installation can be a lot of work. The calipers need to be fixed in the right position, which can involve a special tool to shave a little off the mounts to get them square and parallel to each other, then some precise setting of the mounting adapters and positioning of the caliper on them. Both can be tedious because you need to do the bolts up quite tightly without letting the thing you're attaching move. If you're unlucky you might even need to bleed hydraulic brakes.

But once that's done it almost never needs to be changed. So "setting up the brakes" means changing brake pads and every year or so either replacing the brake cable and outer, or bleeding the brakes. Neither of those should take more than half an hour, but I'd probably still get a shop to bleed the brakes because it's messy and toxic.

Just changing pads is normally quick, even if you have to turn the bike upside down to pull a wheel out. It's usually ~2 minutes plus the wheel removal Cleaning the rotor takes as long as swapping the pads. Mostly it's just a dirty job. I wear disposable nitrile gloves and just use toilet paper to clean the rotor, but somehow still manage to get road dirt off the caliper on myself every time.

IMO the difference in braking power would make up for any difference in hassle, but I've also found that to keep V brakes working properly takes more work than keeping discs working. Setting V brake pads up is a bit of a pain, and they wear out fast compared to disk pads. But you have to redo the V brake setup every time you change pads, where discs you just push the pads out (hydros) or wind the adjuster screws out (cable). It's quick and low-hassle.