What you hear on a site like this are the cases where people have problems because they 1) mod and 2) come here specifically for help with problems. Also you hear from people who have no problems, but not data and you can't get an idea of reliability at all. It's kind of like when you post on Facebook about how shitty Dodges are and a dozen guys post about how their uncle/father/cousin/friend has one with 150k miles and it has had no problems- nice anecdote but we know it's a crock of shit. Same here- anecdotes tell you nothing.
http://www.truedelta.com/Scion-FR-S/reliability-1096 check out this site. It compiles data from owners. The quarterly questionnaire asks if you've had repairs and what they were and has data from owners and reviews. The Twins are pretty reliable.