Completing all three of them puts LBA into a deep comatose (until some new outstanding lens comes along).
Now, where's the fun without LBA?
Seriously, I first acquired the 77, and quickly fell in love from the first shot. When I know that I need something (a portrait) to frame, it's my go-to lens. It's a PF monster though.
Then came the 43. It was, and still is, one of the most difficult lens to shoot with, as it seems to randomly produce sublime, and downright repugnant image one frame after another. Taming it was a challenge. I since then figured out that under lowlight, I'd rather have it underexposed (by reducing aperture at most a stop) and just pull the image in PP. Under good lighting, I go ahead, and even indulge wide open, but it becomes unbelievably ultra sharp at f/5.6-f/8. Wide open, contrasty condition produces nervous bokeh, stop it down two stops, and it renders beautifully. It's like having two lens in one. And when it does nail an image, even a slightly misfocused image, (e.g. more focused on the nose than on the eye) gets framed and displayed in the living room.
I tried to postpone purchase of the 31, and only got it last year. I've two regrets since then: 1) I should have gotten it earlier, and 2) it sent my LBA into comatose, and I'm not sure whether I like it or not
. The 31 renders everything beautifully. It's not as smooth as the 77, nor as sublime as the 43, but it is just as wonderful. Wide open, it's a bit tricky, but set it at f/5.6 - f/8, it becomes a wonderful P&S lens, shot after shot after shot.
PS: For those with budget constraints, the DA*55 is a very good compromise of the 43 and 77. The DA*55 and the 31 will be a great combo.