Note: This was originally posted in 2014 when I made the switch. It's reposted now because of the news last week about Evernote's change in pricing.
I have been a big fan of Evernote for a long time. The ability to keep your notes one place and have them automatically sync to any device is really what "the cloud" is all about. For a long time Evernote was my goto place for storing information. The fact it was the only cross-platform service of its kind helped me like it as well.
Earlier this year a competitor became cross-platform and I have found it works better for me how I like to organize my data. Microsoft's OneNote is that competitor. At the root both services allow you to set up different notebooks for your various needs. However, where OneNote excels for me its use of the notebook metaphor and each notebook is allowed to have an unlimited number of tabs. Within those tabs you are able to have pages. This is opposed to the tagging Evernote does. A good example of this would be a cookbook. You can have tabs for your deserts, main dishes and appetizers and when you are on that tab you can see them automatically. As I said before the metaphor really works for me and how I prefer to set up my things. I suppose you can kind of do the same with subnotebooks in Evernote but it just doesn't do it for me. As they say, your mileage may vary.
OneNote does have its faults. The biggest one I have seen is the ability to get data into OneNote. Specifically getting data out of Evernote and into OneNote. There is no import function on the Mac client. Another oversight is not having the ability to do handwriting. This is something Evernote does allow on their mobile devices with the Penultimate app. I believe these are a major oversights and ones Microsoft hopefully will address in their next release.
If you are on multiple devices and like to have your notes organized you can't go wrong with either of these two services. However for my money OneNote is which works best for me.