Thanks for all the responses! I'm looking real closely at the Sonnet because of gasp (pricing) & because in researching Newertech I discovered Sonnet had hired Newertech employees (hopefully the hired employees are providing quality services). I forgot to mention (it was a long week here with the upgrade, etc.) that I was running Jaguar as the OS. I assume (please fill in the blanks if I'm off base with the assumption) that enabling extensions is in reference to OS 9.x. So, that won't be a consideration for me. The reminder of heat generation is always prudent. Thanks, Tweak. Have you installed any fans in your Mac? If so, could you please expand on the specifics? Also, does anyone have any thoughts about single vs. dual processors? Your experiences will be considered carefully. Ciao 