Currently have a k3 4800.
Really like the exo but get the pack slippage with heavy loads. Looking for advice between the k4 7200 or kifaru ma duce. Not really interested in anything else at the moment.
I have an older Kifaru Frame, I think they called it the Duplex frame (not lite or tactical). I've loved it and used it for years. This year I got rid of all my bags for it except the Ma Duece and bought an Exo K4 with the 3600 bag. I've used both back and forth this year on backpacking trips/hunts and just with a sandbag. For me personally, I prefer the Exo by a pretty good margin. I know my Kifaru is old and the padding is worn and flat at this point so it's not a fair comparison with the new Exo but I still think the Exo is the better setup for me. Again, the Kifaru is great and has served me well for many years. If it was the only pack I could use for the rest of my life I'd be totally fine with that. I just like the feel of the Exo better. I don't have to crank the hip belt down nearly as tight and it stays in place better than the Kifaru. It's the first hip belt I think is actually better than Kifaru. The Exo isn't quite as stiff laterally but still hauls a heavy load really well. It's just a bump up in comfort for me. That said, I have zero plans to sell my Kifaru. It will likely spend more time as a training hauler and go on an occasional backpacking trip where I have to haul a ton of kids gear and the Ma Duece will come in handy, but I'm not getting rid of it either. The Exo is just my new primary hunting pack.
I personally don't think you can go wrong with either setup but if I were you I'd go Exo without hesitation. They have a 30 day return window so you can try it risk free with weight to see if it works for you. If not, the Kifaru would be a great backup. That's my take after comparing both of my frames side by side.