I have a 40 and a 80 IBM. The 40 has been in here over a year and no problems so far, very fast and fairly quiet. The 80 I just upgraded to and it's just like the other, just more space. I paid 102 for it, 99 sounds better for even more, oh well. I also have a Maxtor and a WD, they have all worked well for me.
So far I haven't got one of those 8 meg cache drives but it sounds like there isn't a ton of difference in them according to my friend who builds boxes and servers all day.