TD-H3 is an outstanding piece of kit; I purchased the two-radio kit. You mentioned the TD-H3 lack of IP rating, using them camping hiking, on long walks, then being caught in unexpected rain, and the like, is a concern. With Fall and Winter creeping up upon us the IP 65 rating of the TD-H8 makes it a particularly good option. My other radio is the QRZ-1 Explorer, again without IP rating. The TD-H3 and TD-H8 being able to switch between GMRS and HAM is particularly good. Be aware, switching modes removes your programed settings requiring the settings be reloaded for the mode, HAM or GMRS, one switches to. This will require CHIRP or the TD software using Windows 10 or 11. Odmaster programing software works over Bluetooth to the TD-H3 thus should be installed on your phone be it Android or iOS. It would be wonderful for Tidradio to have their next version of their TD-H3 have a IP68 rating. Also, more power for HAM as the H8 does. Yeppers always trades offs.
The "why not Both" solution. 😛 If you were recommending ONE for a brand new GMRS user, who might some day want to look into HAM, does that give you enough to go on to recommend one? My lack of knowledge self wants to think the H8 with more power and water resistance might be better... but the simplicity and flexibility of the H3 is the other side of the choice for me. Thanks if that can help.
I have both. For GMRS I prefer the H8 for ham I definitely prefer the H3. The H3 is much more clear than the H8. The H8 also has a far broader band usage. Put the long antenna on the H3 and you'll be very happy. The one draw back to both is there is no battery adapter available for either.