Doing it myself
Based on the theory behind the expanding system, I would say crimping is ALWAYS a bad option. The whole idea of the expanding of the pex is that it always wants to return to it's original shape. What happens when you crimp it? Make it smaller? So then wouldn't it want to always go back to it's original larger size? Especially having the pressure inside helping, I don't think those crimp rings are going to last near as long.
Expanding system is "Original" as it was used in Europe for radiant floor. Proven for 25+ years?
How many mobile home crimp systems have we seen with failed crimp rings over and over and over? I do not like it.