Should I agree to amend the onset date?

Yesterday I had a hearing at the Office of Disability Adjudication and Review in San Rafael.  After my client testified and the vocational expert testified, the Administrative Law Judge offered us a deal – agree to amend the onset date and she would issue a favorable bench decision.
My colleague, Gordon Gates, has discussed the advantages of receiving a bench decision, in his blog, The Social Security Disability blog.  Essentially, a bench decision is a decision issued by the judge orally at the hearing.  By stating the decision orally, the judge is able to decide a case faster thereby allowing a claimant to receive benefits faster.  It is nice to receive them.
Yesterday though, the offer was tied to a deal.  We had to agree to advance the onset date (the date my client claimed she became disabled) to a later date in order to receive the favorable decision.  A later onset date results in a smaller past due amount for the claimant (and possibly reduced fees for the attorney).  If you are faced with this dilemma, some of the factors you may consider are:
1.  The strength of your case.  Do you think you have a basis to win if you say “no” to the judge’s offer?
2.  The judge’s reasoning for choosing the amended onset date.  Does it make sense or was it arbitrary?
3.  Whether you need the money now?  Most people do, but is it better to wait to get the amount you feel you deserve?
4.  Whether you wish to wait for a decision that might be unfavorable versus having the peace of mind that you can walk out of the room with a favorable decision.
Ultimately, in my case, we decided to accept the judge’s offer.  We felt it was the best thing to do based on a combination of all the factors.  Every case though is different and you should think about it carefully before making a decision.  The past due amount is the only lump sum you will receive and you should understand the consequences of accepting a later onset date before agreeing to it.