What do you like / dislike about each in your comparison? Have you seen either in person? Also, do you have a dealer nearby for either?
I have a GMG Daniel Boone; I looked at the Jim Bowie but just didn't see the need for the space since it's easy to add a second rack on the rare occasion I may need more room.
About the GMG Wifi stuff: First off, the wifi functionality is a supplement. You don't have to use it; the grill works just fine from the control pad like any other pellet grill. Of course if you're more of a "journey" than "destination" person and prefer sitting by your grill during cooks, the wifi stuff probably won't be of much use. If you're that guy, you can save $160-200 buying a GMG without wifi.
While the remote monitoring and ability to change temperature without walking out to the grill is nice, the real power of the wifi is the ability to set "profiles". These are essentially programmed cooked. As you know, pellet grills usually give the best smoke at lower temps, so on an overnight cook you might want cook at 180F for three hours before bumping to 225F. With a profile it's simple to set it to switch automatically while you're asleep. You can also set a "safety" at the end of that triggering the grill to drop to "Keep Warm" once a certain internal temp is reached on the food probe.
Wifi is a work in progress; GMG is developing and enhancing it right now. Some folks have had issues, though with the myriad of wifi setups and ISP-supplied cr@ppy routers it's surprising there aren't more issues. Just remember that the controller doesn't talk 5GHz, you need to keep it on the 2.4GHz side of your network. If you're using your phone or tablet with the grill, it needs to stay on the 2.4GHz side of the network as well.
Also note that Apple built a restriction into iOS limiting wifi connections when an app is in the background or the phone is asleep; the results in a 10-15 second reconnect when you wake it back up on an iPhone. Kind of annoying, but it's an Apple thing and that problem doesn't exist on Android. Some people pick up a cheap Android phone or tablet for this reason; Walmart has prepaid Android phones for $20-$30, or a cheap 7" tablet also works well. This may or may not be alleviated as GMG moves towards cloud capability planned for later this year.
I'm happy with my GMG and would make the same choice again.