Thanks in advance... When you manage multiple accounts (via an MCC interface) and have literally hundreds of campaigns ... across multiple clients/verticals, is it better to: 1. let the system upgrade itself and see the performance over the next few weeks or... 2. slowly, one-by-one upgrade client accounts before the deadline (July 22)??? Thank you !!!
Its all depends upon you. If you have time then update it yourself, maybe few clients not happy with this , in that case let it apply automatically on 22 july.
I was on the AdWords Support Team for a couple of years. I left just as enhanced campaigns were coming into existence. It has been my understanding the only "pitfall" of allowing your campaigns to auto update would be to campaigns that were originally set up as "mobile only" campaigns. With enhanced campaigns mobile only is no longer an option so when updating to enhanced campaigns there could be an issue or those campaigns may be paused or disapproved. Updating yourself only takes a couple of clicks so I would do it yourself if you can.
If you think the move to enhanced campaigns will hurt your performance (i.e. your site doesn't support tablet) it's best to wait for as long as you can (which gives you about a week from now)