i am wondering what people would consider low, medium and high usage on the hours meters of a Z1..

is operation reading up to 100x10H considered high ? or still medium use ? with drum and tape runs around 50x10H, would that be considered high or medium usage ? Also are there any common faults that happen with a Z1 when the usage reaches a certain range ? If so what would be the ball park repair costs for those things ?

1000 hours of OPERATION is not to me at least considered high useage. Hell my PD170 has double that. Remember though that those are simply hours the camera is ON. Drum and Tape runs in the 500 hours is about halfway thru the life of the heads BUT I just renewed the heads on my 170 with 1540 hours of Drum time. Since the heads on the 170 and the Z1 are virtually the same I'd say you've got a while to go.
Cost to replace the heads, well, I got it for less than Sony but you see, I gotta guy...actually he gave me a deal since I had 2 cams in to him for work so...figure when you do it (if) it'll probably be about $400 to $600 to change out the head and do a minor overhaul.

Big factor is HOW the hours were put on.

If YOU put them on and know they were all in studio, you are probably 30 - 50% through the heads.

If a young guy who specializes in extreme sports in the desert put them on, you are 35 - 99% through the heads.

Adam, before we changed to EX1R we owned three z1s, purchased from a major Sony dealer which handles sales to big broadcasters here. The MD told me that they'd never had to change drums on a Z1 because of head wear. His view (and it's hardly in his interest to say this) was to keep going until you signs of head wear.

I'd bet (though I don't know) that tape deck alignment and spool table tensions are faults that occur far more frequently than head wear in the Z1. I agree - keep running your HDV camera till dropouts become a problem because digital is like a candle - the same brightness on the first day as the last, and then it shuts down.