BMB4 is the oldest baseband that supports LTE. It was released in March of last year. It and MD1 won't do any better that MK7 for reception or signal quality. I prefer MK7 by a wide margin to MD1 at this point due to LTE hand off behavior alone. Couple that with the interface of MK7 being designed around 4.3 vs 4.1 and all that goes along with it, i prefer it for use with 4.3 JB AND KK ROMs.
We will just have to suffer (I don't have many complaints) until 4.4 TW is released by tmo.
I feel the data issues I see are mostly due to kk itself.
Hastily spouted for your befuddlement