I have no experience with perpetual calendars.
The JLC match my heavy rules, like case diameter, dial color, an open case back, mechanical, heritage, uncomplicated lugs for easy strap changes.
What i want on a perpetual calendar is the year in digits.
I can not see if the JLC have the year in digits, but i can see that the dial is nice, so no problem if it have no digits for the year notice, and see a hand pointing at a year is no problem.
I think this is the first JLC that is pretty cool to own.