Obviously the horrible examples being shown could be cherry picked disasters from biased parties so no conclusions are possible at this stage. However the products were retail packaged so not test run rejects or what have you.
These are direct quotes from GW website
"Flash: You will all be familiar with flash on metal models. Citadel Finecast resin flows even more smoothly than metal does in the moulds. This means that a miniature might have very little flash, but some have a lot, which might look unusual. Don't worry, this flash is easy to remove (quite often you can remove most of it with your fingers)."
"Bubbles: Sometimes you will see small bubbles on the surface of Citadel Finecast models. These are easy filled with a dab of Super Glue or, if small enough, will disappear when you undercoat the model."
At least they are admitting that finecast isn't so well Fine Casted
Edit: I'm sounding very negative - I'm interested in painting one.......just having bought forgeworld stuff hoping it's not as bad.