Not experienced with lowa or idahos. Put 1,000+ miles on my summit gtx before my feet flattened and ankle rolled a lot. Had to size up and get stiffer soles with more ankle support. Bought the briksdals after tons of homework. Friend bought the colorados which are just like the briksdals, and the nevadas which are more like the idahos. He hates the nevadas and loves the colorados.
Briksdals are built like tanks but still feel light. A lot more ankle support - dont think I can roll my ankle cause i literally tried. I balanced on the edge of the sole to see if it would let go and it held. Thats impressive. They are stiffer, I got the 4/5 sole, specifically for high country elk/muleys. But not so stiff they dont flex, its comfortable. The outer sole is supposed to wear even better than my old summits but we shall see.
Thoughts on the two and why I picked the briksdal. The crossbow frame is what my friend found extremely uncomfortable in his nevadas - idahos have it, briksdals do not. 10” is a taller boot than the 9” briksdal - personal choice, i have gaiters as you probably do to. The idaho will breath better with more mesh and less leather. Briksdal will take a better beating with more leather but hold more heat. The reason my feet flattened was from the summits flex 3 rating and i could feel that flex climbing steep terrain. Better for stalking close maybe, but harder on your feet over long distances with heavy packs. Idahos are flex 3, briksdals 4 or 5. The lacing seetuo is different too, briksdal is assymetrical and im not sure what that does lol.
If you can try on both and you will know right away which feels better. Good luck!