I finished XB1 and XB2 back to back a few months ago. It's pretty interesting because both games have positives and negatives when comparing the two. For example, I think the world setup and character composition is great for XB1 but some of the writing, particularly for the characters, feels really weak. On the other hand, XB2's world and characters are more derivative (read: anime as fuck) but I like some of the development they had for some of them. The same applies to combat with XB1 having an actual MMO setup with aggro and that but it never expanded beyond while XB2 has a fair bit of variety to it but I don't think the base was quite as good.
Here's hoping an XB3 will nail everything.