I'm willing to not over-optimise it. It may well get turned down by my DM, but I'm willing to just flat not learn spells that would break it (such as Wish, for instance). And I'm not going to be focusing that heavily on Metamagic, and there's a good chance I won't reach the end of the class anyway. I'm not sure how it gets free metamagic, unless you combine it with another feature to reduce metamagic level, as it says it can only take it to +1 lowest.
Mostly I just think I can make the flavour fit my concept, and the other abilities (mantle of spells) are also handy and fitting.