Its probably always worth just damaging your opponent, rather than trying to transform cards like this
A 5/5 flying, trample creature is already strong, but being able to draw one or two cards in your first end step and then up to four extra cards per turn can leave opponents in the dust
(And as Aaron described in his column two weeks ago, Legendary Rules Changes, R&D also realized it was a perfect time to revamp the legend mechanic.) Once legends, or should I say legendary creatures, became part of the block's theme, all the designers started thinking about how to add some new wrinkles to the age old mechanic
And don't you also want to have a friggin' gundam in your command zone, aka Shorikai, Genesis Engine
I can understand how some cards that are more about salt than power, might not seem worth discussing for the sake of balance