Just had a set of Dimarzio Ultra J's put into my Warwick Corvette Standard 5 String passive. Have to say, I'm very impressed. Bass truly sounds much better than with the stock passive MEC's. Extremely quiet (apart from the RF in my apartment), full bottom, well-articluated high and low mids, and a nice zingy top. (The new DR High Beams probaby help with that.) These pups fit right in there, no sanding or re-routing required. Kudos to the few folks who recomended them.