Tom,
Many fantastic photos in your flickr collection. This thread feeds GAS! I haven't made it through the whole album but I will. Europe with a few Nikon RFs sounds pretty much like perfection to me.
Looking at the shots I cant fault any of the cameras or lenses - and I doubt that I would have seen any major improvement in using the latest lenses from Leica.
I have to say I absolutely agree. I recently got an Amedeo adapter for Nikon to Leica M and happened to find a few amazing deals on lenses. I've since collected a chrome 5cm f/1.4, chrome 3.5cm f/2.5 and a later black 2.8cm f/3.5, along with a few FSU lenses to play around with.
Last week I did an informal test of: a V5 Summicron vs. Helios-103, V2 50 Summilux vs. 5cm f/1.4 Nikkor, 35 Lux Asph vs. 3.5cm f/2.5 Nikkor.
My results were surprising. Close up and wide open the Helios was just as sharp and with less falloff than the Summicron. The Cron had smoother bokeh.
The 50 Summilux outperformed the 5cm Nikkor only past medium distances and up close the Nikkor beat the Lux from f/2 - f/5.6.
The most surprising test was the 3.5cm Nikkor vs. the 35 Lux asph. Of course the Lux is much faster but at medium distances and close up, the Nikkor was its match aperture-for-aperture.
The RF Nikkors are truly amazing lenses that perform so well, that I've replaced my 35 and 50mm focal lengths with the Nikkors and I don't think I'll look back. The 2.8cm Nikkor continues to surprise me as well.
Now I'm going to have to find an SP or at least an S2 for these awesome lenses.
Phil Forrest