In the Preferences, there is an option called “Open Effect Editor After Loading It” (Preferences → VST – Plug-ins). It will automatically open the instrument/effect as soon as you instantiate it. This is what you want 99% of the time, since it is assumed that after loading an instrument you want to do something with it 
It saves you the extra step of having to hunt down the track and click the open instrument/effect button. Very useful!
However – it only works if you use the VST Instrument Rack, or you change the instrument / effect in an already instantiated track. It doesn’t work if you add an Instrument or FX track from the Add Track dialog and explicitly choose an instrument / effect from that dialog. So you have to hunt the track down and press the button to open the panel. Ideally the appropriate instrument/effect should always open, regardless of how you instantiate it.
For example if I add an Instrument track and choose Kontakt, I will always have to open Kontakt if I want to hear any sound!
See what I mean? Anyone else think this could use a tweak?