These threads are about as much use as "how long is a piece of string" - every large organisation will have good and bad in it. There is very little way of telling beforehand because everyone's definition of good and bad will vary, and everyone has a different tolerance of "bad" behaviour, or a higher standard to reach before they consider it "good". People will queue up to tell you bad things because it's human nature to moan about stuff. People tend to be less forthcoming about the good stuff, and the day to day stuff that just works in the background, which tends to be pretty much everything.
The only way to tell, is to give the organisation a try if the product fits your needs. If it fails to impress, then move away. However, don't take someone on the Internet's word simply because they had a bad experience with one girl in one branch on one day in one year etc. While it was obviously awful for them, it means nothing in the greater scheme of things as it may not reflect on that persons performance as a whole (bad days, we all have them), that branch or that company.