Spring Theory is spring, not room. I think DM has some delay going on...correct? So that's not really the most natural. I have the Context, as well as the Stereo Wet (and a Supermoon) and I definitely prefer the Wet and Supermoon for how naturally it mixes with your signal, and the way it feels. Context is awesome, but has more of an 'effect' quality about it than the others, IMO.
spring theory has a room mode as well as spring.
I think the room on the SP is great. if you keep the decay fairly short and the level fairly low, its pretty convincing IMHO