Depends on what you're doing.
I, too, am a happy customer of USA Track, but it is intended for use in permanent table-top installations. Note this disclaimer from their web site -
This track is not intended as a toy for children, or for the construction of floor layouts. For best results it should be permanently installed using #6 pan head screws.
In my experience, if you're looking to assemble a temporary floor layout, the very rigid rail-to-tie construction of original Lionel track is best, provided that you can find a sufficient quantity in good or restorable condition.