A 35mm summicron is my standard lens on the Fuji X-E1 (I prefer manual shooting with rangefinders and never got used to autofocus). I have all types 35mm summi's and used most of them on the Fuji - btw the 35mm Summicron is the nicest of the Leica lenses IMHO. These are my experiences:
1. Type 1: nice for b&w, but too little contrast for normal color shots;
2. Type 2: nicest one for the very light Fuji camera: I prefer this type 2 lens above type 3 because of the f-stop tab which makes it easier to change f-stops when a sunhood is mounted;
3. Type 3: also very nice one and provides nice balance in weight between camera and lens (because it has no f-stop tab, I prefer type 2 instead of type 3)
4. Type 4 (so-called Bokeh king): if you prefer a sharp lens but with more coma (softer Bokeh) this is the one too buy - some are not built that good so be aware to buy a good one. It is very light weight I believe also because plastic parts were used - pricewise you might prefer type 2 or 3;
5. Type 5 (the aspherical): if you shoot mainly with fully open f-stop, than this is the sharpest lens. I've used it quite often for indoor shots with available light; but I would not advise it for general use since it is too heavy for the light weight Fuji camera.
Have fun with the summi's (clockwise from below: type 1, type 2, type 3, type 4 and 2x type 5):

Summicrons by
Ron (Netherlands), on Flickr
btw it does also a nice job with a (very portable) Russar lens:

New toy by
Ron (Netherlands), on Flickr
ok and now for the results: here's one I shot with the type 2 cron on the Fuji:

Nieuwkoopse plassen by
Ron (Netherlands), on Flickr