Topic: Switch to EAD or stick with H1-B at work

1. My EB2 PD is Sep 2009 and it's been almost 2 years since I and my wife filed for I-485. We have an EAD/AP and also a current H1-B/H4? H1-B is not currently stamped though. It was renewed again only recently. For the current job, is it better to switch to the EAD or keep working on H1-B? 2. What happens in case of a lay-off while I-485 is pending? In case of an lay-off, is it better to be on H1-B or EAD? Can you file AC-21 and find new employment directly using the EAD or is it more advisable to transfer over the H1-B? Do you become out-of-status even though you have a valid EAD in case of a lay-off or does having the EAD does keep you in status and buys you more time to find a new job that satisfies AC21 requirements? 3. Similarly, for a job change, which is better to use? Transfer H1-B or file an AC-21 and use EAD? Please advise. Thanks a lot in advance