I am a fanatic about functionality and safety. I purchased my system from RVnavigation.com. This system is designed for the MotorCoach industry. It combines several features into one state of the art 7" color LCD screen. It is powered by Garmin's Street Pilot series which "does" allow for the "bus" feature to be set as parameters, thus rerouting to roads that are designed for larger rigs. I have travelled over 10k miles and thru 16 states since purchasing and the Garmin has not let me down yet. The system also has a state of the art Tire Pressure Monitoring system that not only monitors my coach tires, but the TOAD as well. You can see all of the tire pressures on one screen. Plus it will alarm you when any of them go out of range. This happened on a recent trip up I-95 to Daytona. We had a trailer tire go down and were able to pull over "before" any damage to the tire had even occurred. The end result was a new valve stem and we were back in action for only a few bucks and a shot of air. Without the system I could have destroyed the tire, damaged the trailer hub, possible damage to trailer and the contents of the trailer to boot! The system also has a Sony triple camera observation system, with audio. The unit comes with a top of the line radio with Sirius Satellite, iPod jack, CD and a USB port. Yes we can hold more on a memory stick today than all of those CD's in your 10 disc changer you have hidden in a cabinet somewhere. The system even monitors vital statistics on the engine and transmission, i.e. temp and fluid levels. I know my Freightliner info center does some of this as well, but not with the ease and functionality of this unit. Plus my system will alert me on these items if they go out of range. Have I said enough? Is it inexpensive? Well if you add up all of the components, YES it does cost less than buying all of them individually if you want quality gear. However one HUGE advantage, mine are all in one attractive display. No clutter hanging on my dash and the head unit install in the same hole that my factory B/W back-up monitor came out of. No holes to cut whatsoever. Good Luck on finding your unit of choice. I already found mine!