Before I bought my first Leica - a M6 with 50mm lens - 2 years or so ago, I used a Nikon D300 and Nikon D3 with zooms:
- 18-200 for traveling light with the D300
- 17-35 2.8 for wide with the D3
- 70-200 2.8
and primes for faster, longer or light:
- 20 2.8 AF-D
- 50 1.4 AF-S
- 85 1.4 AF-D
- 300 2.8 VRI
and a couple of others
I used the M6 for a few weeks and completely fell for the Leica M.
After the warm up time, I realized, I didn't use the Nikon stuff any more, but wanted some more lenses for the M6, so I sold:
- Nikon D300
- 18-200 (it was only with the Leica lenses, that I realized, how bad a compromise zoom this really is - before, I loved it!)
- 17-35 2.8 AF-S (I got a Voigtlander 15 Heliar-M instead, as I didn't do much wide anyway)
- 20 2.8 AF-D (never used it much, lost it's touch as the light wide prime also, since the Leica is much lighter and smaller as a package anyway)
- 50 1.4 AF-D (I still kept this one after buying the much better 50 AF-S, now was time to sell)
- 85 1.4 AF-D - I sold this lens foolishly in a weak moment of hating it's CA behavior, as I photoshopped a few color product shots. Now, that I almost exclusively work in BW, I do miss this lens very, very much, especially, as I sold a LNIB sample for a very, very low price. I search already for months for a similarly nice 85 1.4 Ai-s, to bring me back this lens.
I bought a Leica 28 Summicron ASPH for all this stuff and never regretted it.
Since then, I got an additional M7, I tried digital with an R-D1 and added a M8.2, which became my daily shooter.
I added a lot of Leica M lenses and just keep the Nikon D3 with my back then 3 most used lenses:
- 50 1.4 AF-S (my workhorse and favorite lens on the D3 - still like it a lot)
- 70-200 2.8 VRI
I only kept this lens, as I shot several F1 GPs in pouring rain, survived other daily shootings in disgusting weather and this lens just keeps ticking - there is no Leica equivalent to the D3+70-200 combo - it is just bomb proof - I do not use it at all these days though. The big, heavy zoom thing just lost it's flavor for me.
- 300 2.8 VRI (my motor sport lens, when not traveling - I use it once or twice a year and keep it foolishly ;-)
I added only two lenses for Nikon F since using mainly Leica M:
24 1.4 AF-S (it's a marvelous, modern lens. I thought, I might use it, but I am just not a wide guy. I used it once and keep it, collecting dust ever since :-( I guess, this is no.1 on my sell list)
58 Noct-Nikkor - I love this lens, it is a drama queen though - wonderful, as it can be, it can be a pain, to focus spot on, wide open with modern (inappropriate) SLR screens.
I am on my 4th SLR body now, to use this lens on and I am still not 100% comfortable (the F3HP so far is the best, to use it wide open)
Nikon has introduced several very nice Zooms since I started with Leica M - the interesting thing is, that I feel not the slightest itch, to try or even buy one.
I am completely converted to primes now. I have issues, to frame with a zoom - too much options, to decide on ;-) I have issues, to use a automatic camera (D3) - I miss the simple and quick manual controls for focus, aperture, ss, ISO.