Well, I'm now a believer. My friend received his 3.5" color signal meter, used it this weekend and was able to receive signals from a satellite for the very first time. He received signals from AMC3 KU and was so excited.
He brought the meter into work today and showed me. Very nice! It even displays the video of the channels you received along with the audio. It's a nice compact unit with a carrying strap and a fold out stand. He said he held the meter in one hand and adjusted the dish with the other and didn't need no TV, extension cord, electrical outlet, etc. The unit is battery powered and then is charged using a wall charger.
I normally use a Coolsat receiver and 7" video flat screen monitor, but after seeing his meter I might actually purchase one myself. This would be great for adding additional LNBF's to your setup like I'm currently doing. With each adjustment you could easily see how it is affecting the signal.