I have been wondering about this myself, this has been an interesting thread. I have what appear to be 2015 Lange RX 100s. Since I got them I've gone from intermediate to expert (Thanks, Taos ski school).
I'm noticing that even with the built-in power straps cranked down and the top buckle as tight as it will go, I still feel some play in the cuff toward the end of the day. Not enough to give me shin bang. I'm otherwise happy with the boots.
I guess my options if I want to address this are to go to zipfit liners or get new boots?
I am looking to get into AT later this season so I would need new boots for that anyway, right? My understanding from this thread and some other reading is that there are boots that will work with both tech and alpine bindings. Should I start looking for something along those lines?