A site called Letem Svetem Applem has put together some performance comparison videos with the iPhone 4 and the new iPod touch, and the results may surprise you. In the startup speed test, the iPad actually beat all of the other iDevices, and the new iPod touch barely beats the iPhone 4 (but all of them were faster than last year's iPhone 3GS, so your upgrade was not in vain). The iPod touch's camera looks slightly darker than the iPhone 4's, and perhaps most interesting, the displays of the iPhone 4 and iPod touch look pretty different. The Retina Display on the iPod touch looks just as sharp, but without the in-plane switching tech found on the iPhone and the iPad, the sides of the display are slightly muddier.
Some of the YouTube comments on the speed video claim that if your iPhone or iPad is stuffed with music, documents, or apps, the speed will be affected, but I'm not sure how much of a factor that actually plays on startup (not to mention that we're talking seconds here -- not nearly enough to judge a purchase by). But Apple's claim that the iPod touch is sporting the same Retina Display as the iPhone appears to be missing the mark a bit. Watch all of the comparison videos right after the break below.