I have evolved to the 1030, I can't see changing from it. Works awesome and like the interface way better than Wahoo. I wouldn't change. I like the idea of the K2 but the lack of overall real world testing or lack of way for me to test it kept me away from it. Just not much out on it.
If I were to have lots of cash and upgraded my power meter I would go sram PM and head unit though, those are legit! I don't need mapping as much as am a data freak.