Kinda like trading a Volkswagon Baha for a Fiat.
I don't own one or have experience with them. To the best of my knowledge, Astra is out of business. I'd stay clear since there's really no aftermarket for them. And no, they aren't a Sig or quality copy of. Similar, but not the same.
The Millenium pro is at least a dependable carry gun. (I'm not a plastic gun fan... But still...)
I would not consider that an equal trade at all.
-Steve