Omni Power Map Sensors ?
 

http://omnipowerusa.com/map_sensors.asp

Has anyone tried them and are they any good?

Since they did not answer my technical inquiry, I said screw them and bought an Apexi-Denso three bar!

Since the Apex'i is a Denso 3 bar, I'm betting the Omnipower is just some other rebadged OEM part.

Don't take my word for it, but I've heard that you were to cross-section the Omni-Power MAP sensors you would be very likely to find a small off-the-shelf PCB-mount pressure sensor housed in a custom plastic enclosure so it can connect to the OEM harness of the intended vehicle. I'm sure the MAP measurement is pretty good, assuming the enclosure has been designed and manufactured well enough to hold pressure and prevent the little sensor inside from being damaged by vibration.

They never answered my inquiry into their product!
So I purchased an Apexi-Denso 3 bar which is known to be of good quality.
Harder to get and more expensive, but !