The MP500 seems like a bumped-up version of the MP450:
Screen: 2.1 vs. 1.9 inches
Accuracy: Small as 1 picoliter vs. 2 picoliters
Time to print photo-quality 4X6: 51 seconds vs. 55 seconds
I would choose the MP450 for $50 more dollars and it has Bluetooth, infrared, and PictBridge.
Just my $.02
~Ibrahim~
P.S.I would go to a store that retails both, try them out, ask the salesman/saleswoman if they'd let you test print one of your pictures.
After just over a year my Epson Stylus C84 just died-I decided to go for an all-in-one, and am trying to decide between the Canon Pixma mp450 and mp500. Any suggestions? If you purchased the mp500 did you consider the mp450, and if so what made you choose the mp500? Same question for those who purchased the mp450. Thanks!!

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