In a nutshell:
The YX510 is the cheapest dual-band cellular signal repeater I found. It's easy to set up, easy to use, uses standard RG-6 cable and connectors, and it works very well out-of-the-box. Definitely recommended.
Long version:
At my parents' suburban CT home, the location, the terrain, and the aluminum siding all add up to zero indoor cellular reception. Even outdoors, my dual-band Cingular GSM service gives me at most 1 bar...all attempts to place a call immediately fail. My siblings' Verizon service is a bit better, but still not enough for them to place calls. Up on the roof, though, I found I would get 3 bars (up to 4, if I held the phone over my head), quite sufficient for a reliable phone call. Enter the YX510. It's easy to install, though their recommended pre-installation test procedure didn't leave me optimistic--I couldn't get the base unit's "signal" light to flash green when placing a call from nearby it on the roof (which the manual said would represent a successful test). The error code I was getting from it indicated either the signal was too strong or the interior/exterior antennas were interfering with each other. Undeterred, I installed the main signal antenna (zip-tied to the top of a length of PVC pipe strapped to our old TV antenna pole, to keep it away from metallic objects, as the manual recommends). I tried another test with the base unit placed at ground level about 35 feet away, seperated by a good chunk of the house, but I still had trouble getting a reliable signal. When I finished the installation and moved the base station indoors (about 20-25 feet almost directly below the exterior signal antenna, with the roof and two floors in between), that's when its performance started really shining. Installed in the basement, the YX510 base station gives solid reception for most of the dual-level, 2600 sqft house. My cell phone shows a full five bars most of the time, for anywhere within about about 15-20 feet of the interior antenna (the signal strength slowly drops with additional distance). Once I start a call, my phone's signal strength meter immediately drops to the strength of the signal at the roof (usually 3 bars), so it's apparent that the included omnidirectional antenna cannot "amplify" the received signal. Thus, make sure you at least have a usable signal level at the point where you plan to install the exterior signal antenna, or otherwise consider getting the directional antenna upgrade for the YX510. My siblings and I now have reliable cellular service for more than half of the house, and we can all use our phones simultaneously with no problem. Very satisfied! (Note: I installed the exterior antenna using the YX012 grounding kit, but one could easily use store-bought outdoor RG-6 cable and a grounded female-to-female RG-6 connector instead of that kit.)