I'd suggest 400 mgs of EQ if you're hitting 600 mgs of test.
I'd personally reverse it to 600 EQ, 400 test... as that system works very well for me. I look "harder" when the EQ dosage is higher than the test... but as everyone knows... I respond very well to EQ. So I use it as a base in 90% of my cycles.
As far as what to expect, there's a lot more into it than your cycle, as you know. On a similar stack, I gain around 12 lbs solid that I keep. I eat very clean, however. So I don't usually gain 20 lbs like some guys around here do.
But at the same time, I've never lost a pound after a cycle.