We love those lenses, they're really really Leica, the out of focus is very different from Arri or Cooke.
If you need sharpness and resolution you can always use Master Prime ...and carry them!
We got a complete set of Standard Speed ArriFlex T2.1 from West Germany (so untill '89) and I prefer their look over Ultraprime with Red's cameras. It depends from the job, sometimes you need Sharp&Res and sometimes not.
Backorder is a pain, our reservation is from March '11 for Q2 '12 and untill now not a sign from BandPro.