I have had a pretty decent amount of success with my Prosports. I do like that they go black when off, but they are sort of difficult to read during sunny days, though I do have some 'hoods' on them, which came with my kit (I think from a MINI vendor, not Prosport)
I think theyre pretty inexpensive too. Also have the setting where you can set a limit, and see your maximum.
here they are, either side of tach (you cannot really see what they say that much...its the flash)
http://i13.photobucket.com/albums/a299/iwashmycar/TueFeb02170523EST2010.jpg