To my experience, the FIH7160_V1.2_WW_01.1529.05 generic firmware is the best available yet (Lenovo package GTWO42WW, version 2.14.10830.4412). Note it applies for non-US customers, there are specific customized firmware versions for US mobile operators.
Unfortunately Lenovo has released another two newer software packages (GTWO44WW and GTWO45WW) containing (older, huh ?) 1528.04 generic firmware that is broken at all. Causes device lockup etc. That is evidence nobody has ever tested these software packages (for non-US customers) 
It seems as the Intel chipset experiment is over because recent WWAN EM7455 modules are Qualcomm based.