Antaniserse: the Steam one, however, is not limited in number of activations, as far as I can tell.
charbon: I'd still take a one time activation over a third party telling me when and if I can play my game (and requiring me to always be online). That's the worst kind of DRM for me, but hey, to each his own I guess.
Yes, always online is the worst, but Steam does not enforce you to be always online either, so by your description of the system used by Runic themselves, we have the same steps for both services:
1. Install the game on a new machine
2. One time activation on a remote server
3. Switch to offline mode
4. Repeat point 1-4 for every different machine, if needed
But, only for the Runic DRM, the additional:
5. After the 10th activation, rely on an additional support service to get new keys
That's why i was arguing it's worse, in this instance...