I used DP1/DP2 and Ricoh GR III/IIIx, Q2 or Sony RX1ii+long zoom P&S on travels... I like the wide for landscapes, std for people shots, but usually it doesn't make sense to carry 2 Q3 size cameras (plus the price) as I try to be on the lighter side... GR set is easier to carry... X100 is in the middle at 35mm with wider angle option.. I am a big fan of Contax g 45mm, but the bokeh is on the harsh side... I like 45-50mm for walk around locally, but usually a zoom gives more opportunity to shoot... There are so many smaller 40-50mm options eg Sony 40/50mm 2.5, Samyang 45mm 1.8, Sigma 45mm 2.5, but they are not at level of Leica apo level...
Sb calculated the crop options in Leica forum:
43mm f2.0 = 60,3 MP (9520 x 6336)
60mm f2.8 = Crop 1,4x - 30,8 MP
75mm f3.5 = Crop 1,7x - 19,9 MP
90mm f4.2 = Crop 2,1x - 13,8 MP
120mm f5.6 = Crop 2,8x - 7,69 MP
150mm f7.0 = Crop 3,5x - 4,92 MP
I wish it will be more 54-65-86-132mm crops ~1.25x, 1.5x, 2x, 3x crops... 85mm would be 15MP... But then you can always crop differently from raw...