I also experiencing this lag since the upgrade (sometimes slow, sometimes normal) only in the last days it seems that are more the "normal" days than the "slow" ones.
What I hate the most is the fact that you cannot copy anymore images from the note and copy them to mail or else. This is very annoying
For sure is a false step for Evernote and I hope they can fix it soon in the meanwhile, going through this forum, I learned that you can still download the old Versione 7 that now has been rebranded "Evernote Legacy" that works side by side with new one.
Nice move . You guys save my day!