TOY: automatic tire deflators

[David Knight <knight@xxxxxxxxxxxxxxxx>]

Hi all,
     I think I'll buy myself some automatic tire deflators this year.

I know of two options:
oasis-off-road trail head automatic deflators http://www.oasis-off-road.com 

Staun Tire Deflators http://www.4by4connection.com/stauntirdef.html

Both sell for $55-60.

Does anybody on the list have any real world experience with either of these?
How did they work out? Were they consistant? Would you buy them again?

Any other alternatives I missed?

Thanks
David