Thanks JBond for the detailed answer. Even if not Nagra I love the design.
I came across this thread twice. Once when searching for info about using nagra III and 4.2 and then when I was looking into getting one for looping. I've got a Nagra SD, had it since they came out, which I love and still use all the time to record music and for field recordings. I love its low noise floor compared to the Tascam recorder I had before and the HHB Minidisc recorder I had before that. I'd like to get another one so that I can get the glitched screen on mine repaired.
I started recording to 4 track in cassette in the early 90's and still do, though I now use a AUDIO-TECHNICA RMX64 rather than Fostex I started with. I use the computer for editing and mixing. I use various tape echoes (echoplex, space echo, fulltone) but nagra is closer to NASA than those machines though I love what they can do. I still use Tweed era tube amps as well.
But I think it's time I got a tape recorder that's built to last. Currently I'm looking for an IS model due to the smaller & lighter size as I record a lot on location.
Richard