Well, I'm with you in that I think the original, pre-Quantum Maxtor drives are better. If you go to the Maxtor site and look at ATA drives, there are three product line groupings.
DiamondMax Capacity family, 5400rpm:
536DX (new)
D540X (new)
DiamondMax 80
DiamondMax Plus performance family, 7200rpm:
Fireball Plus AS
DiamondMax Plus 60
DiamondMax Plus 45
DiamondMax Plus
FireBall entry family, 5400rpm:
541DX (new)
Fireball lct20
531DX
Of all all of those, the DiamondMax are all "original" Maxtor drives and are nice, IMO. The Fireball Plus AS is a decent drive too.
Those DX drives are all made to be cheap. I'd like to know what drive came in the first box you bought, Zonon, but I personally would have returned any other than the DiamondMax plus, which it sounds like you did.
I hate it when companies mess with their products so badly like this. I went to Fry's the other night and looked at their drives on display, just curious about the build quality of some new drives. I've never liked Western Digital drives, because in my experience they have been finicky of the other drives and controllers they were connected to. They were also loud, as in bearing noise. From the build quality on the drive I saw and the reports I have heard here and the few reviews that are out, I think Western Digital's new 40gig 7200rpm line (WD400BB), might be my next drive.