Many of the guys I wheel with run them because they're inexpensive, reliable, and fast.I've seen people's MV-50 fail on them and have always worried about mine failing me.
That warn model's only at 1.5 cfm w/ 150psi max. Not sure what the duty cycle is since it doesn't mention it, but I'd guess it's not 100%.I agree that the 90 would be a nice upgrade to the MV-50, but look at the price? The MV-90 at the link he provided comes in at $159.00 and it has their stupid hose. But I can re-tap it to a standard fitting. I see it has in an line pressure release valve next to the cylinder head. But no mention of thermal protection. Found cheaper ($131.50) here: http://www.lowrangeoffroad.com/superflow-mv-90-mega-air-compressor-mv90.html
The WARN SPC (http://www.warn.com/truck/aircompressors_spc.shtml) uses standard hose fittings and hoses, comes in at $113.00, and it has thermal protection.
I'd probably go with the Warn.
Comparatively the MV90 is at 3.7cfm, w/ 150psi max pressure & again 100% duty cycle.
BTW, if you replace the fittings for either the MV50 or MV90 make sure you use an open chuck style and not a closed chuck since it requires a fitting that remains open.
Just to correct a little misinformation here. The duty cycle on the MV90 is 60%. Q industries recommends that you run their compressors no more than 40 minutes with a 20 minute cool down.
Most, if not all compressors that are not equipped to auto cycle need to have an open flow on start up. They need to bleed the pressure off the compressor head for no load starting. Trying to start against a load will lead to over heating, blowing fuses, and shortened compressor life. You can use most of these compressors to fill a tank, but either the switch that cycles the compressor or the check valve at the tank must bleed the air off of the head before start up.