I've been playing around with the Transcontrol plugin, hoping perhaps I just hadn't yet found the right application for it. My conclusion: I was being overly charitable in describing it as "unimpressive". Free or not, it's gonna be uninstalled.
Here's a sample. First, note how the waveform changes when Transcontrol is enabled:
Transients are gone - just what you'd expect IF you turned the Attack control to the left. But the Attack knob was in its default neutral position. Only the Release knob was turned up.
OK, so it's a transient killer. That could still have some usefulness. But now listen to what the above clip sounds like. The first 6 seconds is with Transcontrol bypassed, the remainder is with it enabled. But you'd be able to tell even if I hadn't told you where it kicks in, because it sounds nasty.
https://soundcloud.com/bitflipper/transcontrol-demo