I too have the B+W. It's certainly not as quick to use as the slide in Lee, however, the price difference and the fact I don't use it all that often means I can live with that.
It would be nice to:
- compose
- focus
- slide in filter
- shoot
- slide out filter
- repeat above
...but then as you say, I don't use the ND enough to warrant the Lee. Aside from the addition of screw in, screw out, I'm happy with the B+W
Interesting.. Wouldn't that soften the image by quite a bit?
In decent light liveview can greatly assist in the process. That is if you have it. 1DsII and A900 don't, but something like 5DII or 1D3 do.