The answer to the mediocre performance of the iPad and most tablet GPS chip is a remote antenna. I use Bad Elf (feel free to Google) and have for many years, mostly in aviation applications where more precise locating is necessary. Since I now use it in the car, it has been hands-down better than the installed unit. There are a few others that work well also but the Bad Elf fits in your pocket and typically shows accuracy around 14ft and less when there is a WAAS facility nearby. It syncs to the iPad through Bluetooth and a full charge will last more than 8 hours of continuous use.