If battery performance is important, go with the Cobras.
I have Midland GXT850 and Cobra Li6700. Both are very nice.
The GXT850 uses the same Midland AVP-7 battery pack that the GXT950 uses. The Cobra Li6700 has a 950mAH Lithium battery while the Li7200 has a 1500mAH Lithium battery.
The Lithium battery in the Cobras totally outclasses the NiMH in the Midlands. The battery life in my Li6700 is absolutely insane. Seems I have to charge the Midlands at least three times as often with similar use.
The battery life of the Li7200 should also be excellent. The larger battery should more than make up for the additional power needed during high power transmission.
The rechargeable battery pack in the Midlands is barely useful at full power. They use 5 AAA batteries (near as I can tell without opening battery pack) to maintain 6 volts but at a loss of battery capacity. AA alkalines probably work great in the Midlands (haven’t tried yet).
The Cobras are overall smaller than the Midlands in large part because Lithium batteries pack more power in a smaller space. I would say that the Midlands seem a little more rugged, but at the expense of being larger. Also, the Midland spring loaded belt clip is much better than the Cobra’s belt clip. My Cobra belt clip hasn’t broken (yet?), but I’ve heard of others breaking them.
The earpiece that came with my Midland GXT850 radios wasn’t all that useful. It worked fine, but it didn’t seem to fit my ear very well. The car charger can be nice to have around (it’s a cord that let’s you plug the desktop charger into an auto cigarette lighter). Don’t know if one is available for Cobras.
Haven’t tried any external mic/earpiece on the Cobra. One possible disadvantage of the Cobra is that the single mic/earpiece jack may not be as secure as the Midland two jack setup. The Midland earpiece has two plugs molded into one connector and holds well enough that I wouldn’t worry about it accidently falling or pulling out.
Hope this helps!