A change in GUI is like inviting the competition in if the product doesn't have a "revert" button. I can see wanting to have a new look for marketing and sales purposes, but the daily users of the product likely have lots of memories attached to what they're doing and how they're doing it and changing everything makes them feel useless. Replaceable. Unimportant. Judged by the makers of the product and found wanting. And that makes it easier to burn a bridge and move on.

This means my writing arm will be in a sling for about 6 weeks. Writing will be extremely difficult — more likely impossible, according to my surgeon — for part or all of that time.
Job candidates can flub negotiations if they fail to recognize that there are two components to compensation. There’s money, and there’s everything else. If you ignore that dichotomy and focus primarily on the money, you miss the point of compensation and you might forego a job you really want. Of course, if salary is the key for you, then much of this advice won’t be helpful. But if you’re open to alternatives to salary alone, read on.
Don’t ask whether you’re a candidate. Tell him that he’s a candidate to be your boss.