I know nothing about the Lawson sites except I rode my bike past there a few times last year. But I do know from attending TBF and all the festivals I've ever attended, always arrive as early as you can possibly arrive, especially for TBF.
First off no matter if all the sites are perfect you'll have better choices, even if that just means closer or further from bathrooms, bus stop, etc... Second theres just so much to do, and so many things going on prior to Wednesday nights kick off the more time you'll have to do things non-festival, and gives you a day or two extra to adjust and settle in. I know its not always possible for everyone to have all that extra amount of time off, but if you can you should.
Listening to:
my kid complain about math homework