Hi Tony, sorry to be so late chiming on on this thread.
I first need to say something about the cost of using Leica lenses. THEY ARE EXPENSIVE! Are they worth it? I'll leave that debate for another thread, another time, but for now I will leave you with the thought that not all of the Leica lenses cost a fortune. There are plenty of used lenses available on the market right now that are both stunning and are reasonable priced - for a Leica lens, that is.
I am particularly fond of the 35mm Summicron, the pre-aspherical versions. I've owned one of these lenses for more years than I care to count and am still stunned by it's performance. It is small, fast, sharp, has a glow wide open that is to die for, and it is hard to argue with a 35mm focal length for use in most every situation. Older versions of this lens can be bought for around $1,000. This lens on your X-Pro is going to give a focal length very close to what a 50mm lens would provide on a full frame 35mm camera.
A 50mm Leica 'Cron has a near 75mm focal length equivalent. Again, a very useful focal length. You can pickup a used 50mm 'Cron for relative peanuts. Even the old collapsable versions work like a champ on the X sensor bodied cameras.
For portrait work, the Leica 90mm focal length works a champ on the X cameras. Personally, the later ASPH versions of the 90mm do nothing for me shooting people, they are simply too dang sharp. I much prefer and use myself an older 90mm Elmarit with it's f/2.8 fastest setting. For a good portrait, your going to be shooting at f/2.8 or f/5.6 even as your fastest setting just to get sufficient depth of field. Why pay for speed in a lens that you don't need?
Of course, my personal favorite lens all around be it on Leica or on one of my X bodies is the Leica 28mm 'Cron. Fast, wide, small, and amazing resolution on Fuji and Leica. I believe one of the best lenses ever made in the 28mm focal length. These will cost you though. Even used, you will be hard pressed to find a beater for less than about $3k.
Which brings up the subject of why? Fuji's own lenses for the X series are pretty fantastic, and very reasonably priced. I am a big fan of the Fuji 14mm f/2.8, which gives an equivalent focal length of 21mm. LOVE this lens, but I love creating wide images. Priced at $900, it is FAR less expensive an alternative to the Leica 21mm Summilux I replaced with it! Fuji's 35mm f/1.4 is also a lens I own and love, and it was only a paltry $600 brand new.
Bottom line, don't judge based upon high cost. Judge with your eyes looking at the finished images....
