I have got the neo 6m v2 gps module connected with my Arduino Uno and it is always blinking Red.
When you first use your NEO-6M, it could take hours, maybe even a day (yes, a day) continuously powered to get it's first fix.
I have tested a lot of GPSs in my time. With a decent aerial, all get a fix from cold in approximatly 60 seconds.
You must've only tested nice modules manufactured in the US with high quality. The cheap chinesium GPS modules can take as long as I mentioned in my previous post. I think it took somewhere around 8-12hr for my chinesium NEO-6M to get its first fix (with decently clear view of the sky).