H-1B Extenstion vs. EAD, Which Is Better?

Dear Gurus,

I'm a 7/2 485 filer. My H-1b will expire in several months. Should I renew H-1B to keep a non-immigrant visa? Or use EAD to work and EAD renewal costs less?

CIS 245 (K) said one can become illegal if his/her 485 application is denied and reentry to US will be difficult. Should I be concerned of this?

Thank you very much for your help!