The Sony PCM-R500 is definatly a tank. Its a self cleaning deck so i've never put a cleaning tape in it, nor have I ever even sent it in for a pro cleaning or anything, just checked the hour meter on mine and it has 3941 hours on it. I used to use it for doing clones a lot back when I traded dats (d8>r500) but now I just use it for DAT>CD transfers mostly.
Close to 4000 hours, never had a problem, seen tons of 60m/90m tapes, definatly as solid of a deck that you can buy. All kinds of ins and outs, but its got a hefty price if bought new, although i've seen them go for as low as 500 on ebay.