The update is a lot of fun: A new character, and some well designed new levels.
BUT the new character costs the premium currency (gold), and many players are finding that they have lost all their gold following the purchase. This happened to me too. The Dark Angel character is currently 30 gold, as a special offer.
It's up to you whether you get it now and hope to avoid the bug / get refunded for any loss, or wait and get it after they fix this issue.
Edit: Roadhouse Games have said on Facebook that they are aware of the problem, have found the cause, and will return all lost gold soon