I stepped into the S system, for the same size and handling reason you mentioned. Now comes the x1 is on step further regarding size and compability. Thats why I decided to go for a x1d and 45 and 90.Me too, the S2 was instantly my dream camera and it was up on a pedestal as far as I was concerned. It unfortuntely worked out more complicated and problematic than that for me though and development lagged in the areas I needed.
Leica was the first to create this small medium format camera and probably paved the way for the GFX and X1. Really it was miracle they could take a medium format camera and make it smaller than a Canon 1 series and especially so back in 2009 or what ever it was - almost 10 years ago. It was truly ahead of it's time.
There's no denying how nice S images look either but there is also a fair bit of marketing at play - the lenses really aren't significantly better than other systems, they are generally not that much faster either. It takes nice images at a very high price.
My last remaining issue was the disparity between the cost of ownership and the reliability and service.
I am not after maximum IQ, I am after excellent IQ in a size which I can bring to the place where I want to take images.
From some first images the Hassy 45mm looks fine to me, even though shooting side by side with the S45mm the difference in vignetting was more than obvious. How much DR does that kill to correct it? Its still ok for me, because on the other side the Hassy 45mm is much smaller.
I have no idea how the S lenses compare to other Hassy or Phase lenses. I once had a Hy6 with some Rollei Schneider and Zeiss glass and I also really liked those lenses. All I can say is that the S lenses I have used seem excellent in every regards so far. Are they better, equal or worse to Phase lenses? I dont really care.