Just went through this decision process.
Electric (remote)
More room in the most crowded area of the car.
Controls flow better
Gains 10 to 20 HP
More wiring
More plumbing
More expensive ($320.00)
Same weight
Mechanical
Simpler plumbing
Less expensive
Less room
Poor flow control
HP loss
www.Meziere.com says controllers are not even necessary, the electric pump has better flow dynamics overall than mechanical without any flow control. Pretty convincing when an expert gives advice that potentially means he's going to sell less product. Think about it, a mech pump runs too slow at idle and too fast at red line. If you run underdrive pulleys for high rpm driving then it's going to overheat in traffic. The pump is wired direct with key on to make it more fail-safe.
I think the HP gains might be exaggerated when they say 30 HP because you have to figure you're loading the alternator at least a little. Maybe their talking about at 8 grand on a race motor.
Mounted inline near the engine with 1-3/4" hose inlet and 2 -12 lines to the engine. Bagged the expensive and bulky adapter plate at the engine and went with two small 3 hole alum plates with 3/4" NPT holes for the -12 lines. Really simple to make. I even cut down the water pump face of the front cover.
The only thing I don't like about the DC is it's nylon, the Meziere is all aluminum including the impeller.