I have an AV8OR and find it very good for the very low price I paid for it - around $150 brand new a couple of years back.
That said the Garmin units are clearly more robust, the screen is better and the yoke mount better too.
In addition to the AV8OR I have recently also started using a Samsung Galaxy 3 running the Garmin software - $130 for the tablet and $75 for the software - I use it as a backup in flight (I fly hundred mile plus trips over water and I do like to know exactly where I am) - I also use it for flight planning. The internal GPS works fine - am thinking of adding a Bad Elf external GPS linked to the tablet by Bluetooth.
If you have the cash buy a iPas Mini and an externsl GPS receiver plus the Garmin software - hsve better functionality than Android from what I've seen. I also have my POH and other documents on my tablet - they really are very useful.