Had to reconfigure a few things on both my and my wife's EVO but nothing terribly difficult. I've enjoyed the update. Our EVOs are definitely snappier all the way around (example - bringing up bookmarks). I like the UI tweaks in messaging and also like having all volume controls on same screen (ringer, media, alarms, notifications). I like being able to set apps to auto update. There are little improvements in many areas. Don't expect more from a .1 bump.
Only things I had to work through were getting my apps to show up as downloads in the Market (simply powered phone off and back on and they showed up), reconfiguring update frequency for apps like news, stocks, etc to conserve battery. Reworking the 'display as' setting for each contact I have syncing from my MS Outlook account as they flipped to first/last order and I wanted last/first order, and re-doing Swype (uninstalling, reinstalling installer from the original beta invite I received, then reinstalling Swype from the Swype installer). Those were about all of the tweaks I had to make following the 2.2 update. I don't consider any of them 'issues'. Really pleased with the update.