I had a Sizzix and decided to buy myself the Cricut E2 when it was on sale this past winter. I like being able to adjust the size of the image, cutting multiple images at once, the ease of storing cartridges and all the choices on one cart. I buy my cartridges on eBay and other sites for considerably less. I haven't paid more than $30 for any cartridge I have.
I didn't care for the sizzix because it was heavy and hard to bring to crops. It takes longer to do something (for me), especially when doing a title or something with words. I also "inherited" a bunch of dies when I bought the sizzix from a friend. It was SOOO much. I didn't have the room to store it and it was too have to bring to crops. ETA: I had the original Sizzix machine.
That's just my 2 cents.