Agreed. The costs vary a lot too: the US is pretty good ($100/5 years, includes precheck), but you would have to travel a fair bit to make it worthwhile in the UK (£50/1 year + £20 registration).
The only difficult part was setting an afternoon aside to go get scanned/interviewed (if you even want to call it an interview, as I believe I was asked only one question: Why do you want this?).