Price: The price for The Sneaky System is initially $9.95 for part 1, then $97 after 7 days for the 2nd part ($106.95 total). The full price for InfoProductKiller is a whopping $0.05 higher at $107. The Sneaky System is better in terms of price if you were just going to get part 1 and stop there, but InfoProductKiller would be cheaper if you intend to get the full course if you can find a discount code (there was one as a WSO a while back).
Content: InfoProductKiller seems to have more content, since it includes pretty much all the information in part 1 of The Sneaky System and has information on how to profit from Christmas shopping on top of that. It also has a section on how to make images using both GIMP and Photoshop whereas The Sneaky System shows how to make a very basic image using paint and tells you to outsource it instead.
Clarity: The Sneaky System is better organized than InfoProductKiller and takes everybody through the process one step at a time. InfoProductKiller on the other hand, keeps referring to sections that you may not have gone through yet, which is a bit annoying. InfoProductKiller does a better job at showing real examples though, which makes it easier to understand what the course wants you to do. The Sneaky System is mostly reading from different slides.
Conclusion: When reviewing both products side by side, The Sneaky System seems like a cheap ripoff of InfoProductKiller. Not only did the course come out after InfoProductKiller did, but it also doesn't offer any new information. I've seen nothing in The Sneaky System that suggests that the information has ever even been applied successfully by the creator of the course other than the one screenshot on the sales page.