barbwire,
I just had a sending unit fail on my electronic gauge (westach) after about 14 months of use without a snubber. I ordered a mechanical gauge with an isolator (runs ethylene glycol to the cab and not diesel fuel). I realize that leaking either fluid will not be a good thing, but I need a reliable set up. Just my experience so far. I have a buddy who has had a mechanical gauge for a year with no leaks. Put a snubber or needle valve in line or it may vibrate (especially if attached at the VP).
-Jason