The first one you list is hot-swappable. I had heard of them, but never have come across them until now. I'd love to know how they do that, technologically. I understand the SCSI ones, but how do they hot swap IDE drives? They also look like much better quality than the ones I'm using, which cost me about $12.00 for one frame and sliding tray, and $8.00 for spare trays.
I happened to be in Miami yesterday, and also saw a number of others, like the ones I use, for about the same price, at various wholesalers. Apparently, there are a number of generic ones out there, all made in Taiwan, with the only difference being the packaging used. All no name companies, all made of plastic. But I can't complain, never having had a problem with any of the ones I and many others have used. They are quite sturdy.
Len |