I think its better to work in OPT than in H1B since you will save the 33% taxes.But if you have intention of applying GC, then better to get H1B and ask your employer to start the process.Further with OPT you don't have any problems changing your job either you don't like job,boss,company etc because you are not tied with employer.With H1B there is serious problems if you don't get job when you want or have to change the employer and you don't find one within a month time.So there are pros and cons on everything so weigh them according to your interest and situation and act accordingly.