I have made two pens from Chilean Lapis and they were the most difficult. But that was before I started using my "Woodchuck" (I have CSUSA"s version, the Ci0 Easy Finisher). They say that Arizona Jade is the hardest of the TruStones to turn, even suggesting the use of a metal lathe, but I didn't think it was that bad at all. I used the Woodchuck to turn it. If you don't have one, I highly recommend getting one...great investment, especially if you plan to turn a lot of TruStone.
As far as if Chilean Lapis is harder to turn that Charoite, I'm not sure as I have not turned Charoite. R and B Crafts has it listed as Moderate so I would say Charoite would be easier.