I believe the XLII has larger ceiling height then the H. The H does have taller storage below.

According to my visit at Prevost in NJ there is no maintenance you can do on your slide. If there is I would like to know it. They said the worst thing to do is to run it in or out with out the door open. The small windows do not allow enough air to not effect the seals.

I have heard that dry graphite in the slide lock holes can be beneficial, but not from Prevo.