I would like to use apps I get from the Apple App Store, but I wouldn't recommend using Evernote from that store at this time until they get a bug fixed. The bug I'm referring to is the Save PDF to Evernote function in the Apple Print Menu dialog is not working. It acts like it is saving the document to Evernote, but nothing gets saved.
The one work around I have found is that you need to remove the version of Evernote you downloaded from the App Store and then download and install Evernote from their website. Then reboot your Mac and it works just fine.
Its kinda frustrating and I hope Evernote fixes it quickly.
One note, I am really liking Evernote 5.0. It is definitely worth it.
Check out the following video.