Excellent point about the security lines at FRA, but they vary a lot by destination. Security for the US bound flights are very long -- sometimes hours -- while security line for Schengen zone is a minute or two (rarely more in my limited experience). For non-Schengen such as UK it can be 5 minutes when the line is long. It really is only the US-bound security line that is awful at FRA, however if you are flying F on AA you skip most of the line and it takes 5 minutes at most. Flying LH it takes 5 seconds, but that is another story.