I anchor the tube track as little as possible.
1 per joint in the curves max.
An 0-27 oval might get 8 screws.
Until the straights are over 4 pieces long, they wont get one on an oval.
On long straights, its one every three pieces.
Use Lionel/Ives track clips, and you'll really only need two screws 
Its a shame the tracks are produced lighter than before vs thicker/better.
One thing I used to do, I don't think I could today, is pick up a small oval track and carry it to another room.
The O was ok. But 0-27 was an iffy proposition even back then.
I think it might just droop and bend under its own weight, let alone withstand mild contact with another object along the way.
