First, congrats on your purchase. I'm sure you'll like the 31, It's a very good lens. I never warmed up to it, for some reason (I actually prefer the crop sensor DA21 for an equivalent FOV) but the 31 is a lens with few flaws.
Originally posted by neokind My problem with the 43, so far, is that I already have the 35 and 40 DA ltds, and they're great. The extra stop of speed would be nice, but I'm not chomping at the bit to order it...yet.
On APS-C, the 40 and 43 are mostly comparable. The 40 served me well for many years.
On full frame, however, it's a different story. The 40 can be used, but the 43 positively shines. It's not my "best" lens (the 77, 100 WR and 60-250 struggle for that position) but it's my second-most used lens (close after the 16-85). Its focal length is natural and comfortable, it delivers superb results with more pop than the 40 (less even maybe, but more noticeable).
Do you actually often carry and use both a 35 and the 40? They are mostly redundant.