I try to add some additional information with my poor English. I hope you’ll understand and enjoy.
Though I’m not a Patek admire and sometimes critical to their productions (have written in Chronos Japan), still Patek makes excellent watches and furthermore, quality is improving year by year.
As to annual calendars, I have not phased "leverage type" mechanism cause of its complexity. But Lange annual might be a great exception, thanks to large (for me, too large) leverage mechanism, the watch can carry instantaneous calendar. If without instantaneous changing, leverage system means nothing for normal annual calendars. But I say, I personally do not value a base movement of Lange annual.
I've estimated that MIH is the best annual calendar, if you can bear its masculine size. Patek, very well constructed and useful, if you can bear its price. Lange, good mechanism but be careful to avoid shock.
HIROTA, Masayuki