I'd add data collection/privacy concerns that list too. "search suggestions" seem great until you see that often every letter you type is being sent over the wire for analytics and to mine for personal info to sell to 3rd parties. The site even mentions how useful it is for them to see what people are searching for. I don't know anyone who hasn't ever typed or pasted data somewhere they didn't mean to and it's painfully easy for sensitive data to get leaked this way.

That concern won't apply everywhere, but it's worth keeping in mind. Even when my interactions with a simple menu are recorded (for analytics/profit) and reported the amount of data they get is at least limited.