I believe that v 3.10 defaults to GTK-3 in the build, but one still has the option to use GTK-2 (or fb) if they prefer. I prefer GTK2 visually, but I'm good with either for this tool.
In regards to resources vs size, I only look at ram usage. Ie, I can download over 4GB of Knoppix, yet in the task manager, see only 200m or so being actually used by ram.
Kind of like in TC itself. Sudo cache-clear ; free -m is my friend.
Then again, part of TC is to be able to manage and customize ram usage by utilizing different strategies for on-demand, on-boot and so forth to control resources depending on our needs at the time. Perhaps make many different custom boot usb sticks each tailored to a specific need... But I'm preaching to the choir right?
But thanks again for the tip. I'll keep that in mind.