Which one would you guys recommend and why?

I know that mechanical gauges are supposed to be more effective/accurate. Can someone explain the technicality behind this?

Keep in mind I'm looking for a water temp gauge. I don't trust the one in my CRX anymore - I know that it isn't very calibrated at all, so I'd rather have something that gives me a better idea of how hot my car is running. I don't know how accurate or inaccurate water temp gauges can be.

I've seen mechanical gauges at Pep Boys for $13 by Sunpro, or I can get an Autometer for $60 on Summit. I also saw a electric, digital water temp gauge on Summit for $35. Basically, I want to spend as little as I need to for a gauge that is fairly accurate and durable.

Thanks for the help!

Alex