Honestly it works really good in the field. The problem is you have to plan our and download in advance. If you do last minute downloads it could take to long and the download won't complete. If you plan your trips ahead of time it's an easy thing to work around.
Once we're out in the field it's been flawless. The signal connection has been extremely good, and the tracking/route tracing works great. The large number of individual layers is excellent and allows us to plan our trips based on multiple factors.
Overall, despite the cost, I would recommend Gaia. It's a great tool when you go off-grid. I'm now also trying out On-X Offroad as well for future trips.