I also switched over a year or so ago and find it a significant improvement with one notable exception: in TST when you hover over a collapsed tab group it would show you a list of all tabs in the group while Sidebery doesn't. Similarly when closing a group Sidebery doesn't show all of the tabs that would close, just the total count.

I submitted a feature request a year ago but got no traction, and now I just expand and re-close groups before mass closing to double check if I need anything.