True - however (and this *does* depend on who does your mapping), you can enable/disable the map, the Revo map can be turned on/off with a switch (costs extra though).
I'd ask about a bit with the tuners here, often you can use VAGCOM to enable/disable the map with some of them here, but it all depends on what you're looking for.
Having had a tuning box myself, I can only say that fitting and removing for every service (4x a year for me at 10k services) was just a pain in the backside for me. The box itself worked well. Since then I must admit my tuning has gone well beyond a tuning box, but it is not bad