scorsesefan
Veteran
I suppose it depends on how you define "low light" but I find it more than adequate in what I would consider "normal" low light situations. I've definitely used it on some very dim shoots and been happy with the results. F4 isn't exactly "fast" but it's pretty good considering the FX6's Hi Base.
There are times when I wish I had another stop but that's always the case, and I'm happy to trade that stop for IS, especially when it comes to R&G stuff. The implementation of gyro-stabilization in post still leaves a lot to be desired, enough so that I'm hesitant to buy any more non-IS lenses for the time being (aside from specialty primes and the like).
Yeah, having to up the shutter speed in order to stabilize in Catalyst is something I definitely want to avoid...