I always prefer mechanical tbh.I used the sender type when i was running a standalone EMS on the 300zx but that was only because the ecu required it.
Ive hear that mechanical are not overly accurate and can have a slightly delayed reading to the guage than electronic but i think it's minimal tbh!
Plus when you go to check the oil pressure on your car what do you do....plug in a mechanical guage
![evil :evil:](http://www.golfgtiforum.co.uk/Smileys/modern/evil.gif)