Inshop: I think your lawer is misguiding you in few ways,, first: If your I 140 is denied, your H1 is not revoked. I always thought, I 140 is RFE'd if your company cannot pay you or you or the paperwork is incomplete,, you get a chance to fix that issue. If your 485 is denied, you get a chance to appeal. You are not ordered to be deported. Applying for EAD does not cancel your H1b, you are still H1 and can apply for transfer to your new employer istead of using your EAD.
Get this,, if you dont apply now,,, you are going to be fighting a long que man,,, There are so many ppl who will take this opportunity to apply with concurrent 485/140 that your application will be literally wayyyy behind most of the other ones..offcourse, not to mention about the weak economy and the employers attitude towards H1b's... its atleast better to have a EAD...
Offcourse, you are the best judge