Well, in regards to DoNs - there are regulars present even at the lowest stakes in every poker room I play! Sometimes it doesn't matter - 1 or 2 at a full ring table - that's o.k. but sometimes when the number of regulars grows to 3-4 it's difficult to get ITM. Besides more and more people know how to play them... and these who don't know are lucky way too often!
Anyway, I agree with Doomdy - only multitabling plus a good rakeback deal can make them profitable and "playable" in a long run.