Many thanks for the informative replies.
I have to admit that I always went on "how good it looked" at the MAPT and whether I was happy or not would be the deciding factor.
I was asked the question last week and was stumped at that moment to come up with a logical answer. Don't you love the ATO's eyes looking over his glasses at you with a smirk on his face!
As always, Chimbu Chuckles you are a wealth of knowledge!
Again, thanks for the discussion people
