You'll find anecdotal evidence to support any kind of brand on the internet, and sometimes some crazy people make it their mission to ensure everyone considers their own personal experience to be absolute truth.
I have a whole server full of green drives, and over all the years the only problem i had was one drive which was DOA (got a replacement from the vendor immediately).
The performance is fine, considering they are not high-performance drives, and not meant to be. They can do consistent 90MB/s in my setup, plenty speed for some media storage.
Maybe today i would buy other drives, the market changes over time, prices adjust, new models appear, but i would certainly not replace all my green drives just because some troll on some forums claims they suck - but i'm also not tied to any brand for future upgrades.
For everyone praising on Seagate, remember that horrible firmware issue in 7200.11 which frequently completely bricked the drive?
I'm just saying that no company is any better, and everyone has a history of some problems.
The beauty of FlexRAID is that one drive cannot bottle-neck your pool (unless you go realtime raid and have that slow drive as parity) - otherwise it may be slower when you read files which are on that disc, but it will NOT slow down any other discs, which would be considered "bottlenecking".