No noise gate will ever come within a country mile of my rig. Period.
I have yet to try one that doesn't screw with dynamics in some way.
Some noise is reasonable and expected with a high gain rig. If your rig is so noisy that you need a noise gate, don't put a band aid on the problem. Find the source of your noise and fix it for good.
I use noise gates sometimes when mixing a recording, but even in that case, there are other preferable options.