When I tried the 1.0 release, the effect was either too subtle or too obvious. If I turned it down to where I no longer heard that annoying pumping, then I could hear very little difference when I bypassed the plugin. They've since added attack and release controls, which might enable you to mitigate the pumping effect, but I haven't revisited TrackSpacer since so I don't know.
When evaluating it, close the UI and listen as you alternately enable and bypass the plugin. Even better, automate the control so you can listen as it turns on/off/up/down - without watching the cute display, which can visually trick you into thinking it's doing more than it is.