the mr dv is my favorite one. i've had no surgin problems. it just held boost alot better and was OEM! i had a forge before it and i felt a difference when i switched.

 

It seems to be a hit and miss kind of thing. I put one on my car and it held boost worse than stock, stalled at low speeds when I put the clutch in, and surged. A few people told me I had it on backwards but it was the same orientation as the stocker and I tried flipping it for $hits & giggles but the hoses aren't long enough for it to actually go on backwards. Switched back to stock and all is well. Still have the stupid thing sat in my garage.