Alex, maybe you'll come to love the tab... I do.
I also like the smaller size of some Leica lenses, but it also goes the other way with such as the 21 and 24, which flare out to a larger filter size at the front than the equivalent Biogons. My old 35 'cron is tiny compared to the 35 Biogon but there's a lot of optical progress between the two. Enjoy your new 'cron ASPH!