We operate a trucking company in rural Kansas. We made the switch from permanent phones to hand-held phones in Jan 2013. We installed our first Sleek at that time with good results. After seeing that this would be a viable alternative to the permanent phones, we converted the fleet. Because we had permanent install equipment before, installing the Sleeks was simple. We mounted them to the custom fit brackets previously used for the permanent phones, and used the hard wire kits to connect to the previously run power leads from our old phones. By purchasing an adapter through our local electronics store (SMA to mini UHF) We were able to use our commercial grade NMO mounted antennas. Everything is clean without wires being visible. The performance is comparable to our permanent phones, but audio quality and convenience is vastly improved because of using a Bluetooth headset. This is the main reason we switched as it's illegal to talk on a phone without a headset in a commercial vehicle, and our old phones didn't support this. As a rule, we see 1-2 bar increase in signal strength. As a quick test, my wife and I headed to a town 30 miles away with acouple hills where a handheld phone would loose service. We both have Motorola Droid's. I had one in the Sleek, and the other was 'barefoot." The boosted phone maintained signal the entire trip, (as our permanent phones did# whereas the non-boosted phone dropped signal in the usual hills. Of interest is the non boosted phone went between 3G and 4G while the boosted phone was on average 2 bars better on signal at 4G. I say this because our 5dB dual load antennas were made strictly for cellular and not the frequency that data operates on. We purchased a total of 6, 4 Sleek 3G and 2 4G-V) For a simple solution that seems to perform well for the price, we are pleased with our purchase.