Please help on H1-B extension question <-- Xiaobaitu and mytwoce

My H1-B extention was filed about 1 month ago. The current H1-B will expire in two weeks. Recently a good career opportunity at another company shows up and I am debating what I should do.

Since the current H1-B will expire really soon and the extension will most likely be still pending for a while, can I leave my current company who is sponsoring the H1-B extension and move to another company before the H1-B extension is approved? Or I better stay with current company until the extension is approved before I make any career move?

Many thanks for your help.