I highly recommend the crystal mod.
As a gen owner of both the 45 and 42 I can say that the AR is way stronger on the 42. The 45 has a more domed crystal and the AR is not a necessity, but for the 42 it is a must to really capture how the dial changes color.
I have been wearing my 236 since it has arrived, but last week I went with my gen Sinn u2. I noticed my power reserve was terrible, about 6 hours if off my wrist. For something less than 30 days old this is unacceptable. I am guessing its the movement issues everyone else is complaining about.