When my company looked into getting a SAN appliance we were basically on the fence between equalogic and lefthand. We eventually settled on LeftHand. I think our deciding factor was the cost to a virtual san appliance for another office of ours. I'm not sure if equalogic has that feature and the sales reps were much worse than the sales rep for lefthand.
After about a year of use though, and the fact that we use Dell products for pretty much everything else, every time i have to call LeftHand/HP support I deeply regret our decision. I don't think I've spent any less time than 3 hours on the phone with them with 2.5 of those hours being hold. Once I get a tech they are knowledgeable and helpful which is good though. I am much happier with Dell support in general though.