> Is there any advantage (or hidden power) to using the group selection tool as opposed to
> marquee selecting with the default selection tool?
Yes. Two big ones come to mind.
The Group Selection tool can draw a marquee anywhere on the timeline. Even when the tool is over a clip. When you have a busy timeline, hitting GG is faster than finding a spot that's blank enough for the default Arrow tool to draw a marquee.
Also, Group Selection can be used in an unorthodox way. When selecting or opening a large number of clips one by one, for example to change filter settings, the default Arrow tool is prone to mistakes. If you don't double-click fast enough, you can end up moving a clip that you intended to open, thus changing editing decisions by mistake. Switch to Group Selection and it eliminates the problem. Double-clicking still opens a clip, but Group Selection is incapable of dragging and dropping -- it only highlights and opens. So it's great for selecting many clips in a group, many clips in different clusters, and so on. You can use Group Selection to select the clips, and only switch back to Arrow once all the correct clips are selected.
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