I got this hard Disk cheap from a local car boot (actually a few in a lot), one of which is a Seagate but when plugged in the 1200 was having none of it. Wouldn't even read the drive spec! Got no idea of the size but it's no bigger then a 100Mb at a guess. Something about it not being a compatible/valid SCSI drive was the error I got from it when asked to read the config.
No nasty noises either appart from the usual loud wirring noise you usually get from old Seagate's, the one thing I spotted was it was designed for Compaq notebooks so maybe it has Compaq firmware installed? IDK...
I have never known a 2.5 HD @ >4GB (especially old Seagate's) like this not to be Amiga friendly. :-?