The self described geek at the mac store said if I added the 4 GB kit to my new iMac it would be as fast as the more expensive models. I bought the less expensive 2GHz intel Core Duo/ Memory: 1 GB 667 MHz DDR2 SDRAM. It's pretty darn slow..just like the G4 I've replaced. Could someone please comment on this? Should I take it back and upgrade and spend $600.00 more? This was an impulsive buy. Thank you!