I recently switched from dual SB-105s to dual S&S YS-D1s (which I love). That being said, I also loved my SB-105s but there are definitely limitiations you have to adapt to. Lack of TTL is not an issue for me since I shoot in full manual. It was a little bit of a PITA to only have three power settings (Full, 1/4, 1/16) which means any change is a 2-stop change. But you learn to adapt. And I mostly shot with them on 1/4 power and then adjusted my subject-camera distance &/or f-stop to get what I wanted. The biggest proboem is getting them serviced if something goes wrong. No one seems to want to touch them anymore. I live in Los Angeles where's there's a walk-in Nikon-operated factory repair center and they farm them out to someone up in the Bay area where the minimum repair charge is $224.
FWIW, if you've still got your heart set on SB-105s (they're compact, run off of AA batteries, and are powerful), I've got 6 - 2 working great and 4 in various stages of working/not-working - that are just taking up space on my shelf. Contact me privately (kenkurtis@aol.com) if you're interested in giving them a new home.
- Ken
P.S. i am aware of current process where nikon changes 103s with 105 s for free, but
that cannot be the only reason i suppose
According to the folks I talk to at Nikon here in LA, they stopped that program in the middle of 2012-ish.
- Ken