Mine has been amazing, never had any problems with it (although I have only ever used Apple ready parts in it for everything except hard disks and optical drives).And sorry, I was unaware of the slower ram on the 167MHz bus issue - never had to deal with it I suppose as my MDD had a 167 bus to begin with :p Hope all goes well with the O/C! 1.25 should be easily attainable depending on what process