I rented GL09P for 2 weeks, used in various Hokkaido cities and in general the connections are good. I am using it with iPhone5s, iPad and a Samsung S4. Somehow the connections with iPhone and iPad are more stable than S4, but I guess it was not an issue with GL09P.
Only issue I have is that the device disconnect from time to time during the drive, and have to "wake" it up (by pressing the information button).
Other perspectives, no issue with delivering the device to my first hotel, and I dropped the delivery package in my last hotel in Sapporo within 10 minutes. The 2-week plan is also a good bargain.