A few days ago, ie about a month after receiving my 2 x 120GXP replacements ... surprise, surprise ... one of them failed. Hitachi/IBM's DFT test reported "Defective components" - that's 3 out of 4 120GXP's that have failed when RAIDed. This second batch was made in China, Nov '02 - they were of the "recycled warranty replacement" variety.
I refused to accept another 120GXP as a replacement (and would have preferred to change brands altogether) but since they could only replace with the same brand under warranty, they gave me 2 new 60GB 180GXP's for a small upgrade cost.
The 180GXP's have only been in for 24 hours ... but they already seem smoother for some reason, but not faster on benchmarks. I hope this will be the last need for a changeover.
Final comment: IBM drives seem OK for single drive systems under normal use. But when they're RAIDed and used often, ie. daily defragging, transfers & backups etc. they don't seem to cut it.
(PS. Since the first HD failure, I now backup 4 times a day!)