I have two Shearwaters after a poor experience with two VRs. I can use VPMB, VPMB with GF or BuhlmannZHL16. Or, as I am doing now one on VPMB and one on Buhlmann. It served as a backup light in caves in Mexico and you can see the thing for 10-20 feet even in the mud hole we call Lake Travis. Buttons are easy to use even with gloves and the screen is easily read(color!) by those with fading eyesight. Did I mention it took maybe 5-10 minutes to figure out the entire interface, pretty intuitive. X1 is small, hard to read and no color indications.