The annoying thing is that a lot of the time the GamersGate version of a game does have the DRM removed. But you just don't know until you buy it - since so many of them have it intact, it's a total gamble. I really wish they'd say so one way or the other on the game's page.
Oh, and if by "that nasty SecuROM stuff" you mean activation limits, yes some games have those, but they're totally meaningless - GG's own policy states that they'll supply unlimited activations to owners of affected games.
Anyway, I can vouch for GG. They're good. The new 'client-free' setup makes it a bit fiddly to create backups of the game installers, but other than that I have no complaints.

frostcircus, have you tried Steam? If so, how does it compare to GG?

There! Zolgar spoke in the first person! Are you improving, or what? ;-)
Back on topic...
Since Paradox has the publishing rights for Majesty 2, I'm inclined to think they have the rights for Majesty as well. Of course, it may be otherwise.

I prefer GG, but Steam usually gives me better download speeds. GG has the advantage of not forcing you to run an app in the background whenever you want to play the games you've bought.
To be honest though, my main reason for choosing GG over Steam whenever the choice arises is that my Steam games list is more than a page tall, so whenever I'm installing a new game I have to scroll down every single time I want to check the download progress. It gets annoying.

take some games out of your favorites... or put the downloading ones in
or move downloading game above your games list

Can you install from those backups without having to activate?

NVM

No, the installer requires internet access.

Rats.
When you said backup, that got my hopes up for a moment. I realize now you meant backup in the sense of saving bandwidth having to download the installer again, not archiving in case the services goes down. Oh well.