DBQ was PURE GOLD in my case. Even though I can barely walk at times, and am extremely limited in what activities I can do the SHAMELESS C&P examiner wrote "No Pain, No Limitations, Full Range of Motion". On advice of Jason Perry I had a DBQ done by my treating Orthopedic Surgeon, and my ratings went from 10% to 80%.
I would strongly suggest you download the DBQ for your condition from the VA website, hand the HARD COPY (not electronic) to your own physician to fill out. Then GET THE HARD COPY BACK from your physician, DON'T LET THEM SEND IT DIRECTLY BACK TO THE VA (like the VA wants).
This way you will have ample time to review it for accuracy and take it back to your physician for any items that need to be clarified or corrected BEFORE the VA gets a chance to enter it into their system for record. Also, if you give the DBQ back to the VA before the initial PEB findings, they might just say "it was ALREADY taken into consideration" and try to deny its RE-use in a VARR.
When you get your initial PEB findings (which will be low-balled thanks to the faulty C&P exam), you can and should request a VARR in conjunction with a PEB appeal. I opted for a FORMAL PEB appeal, and as soon as the PEB got the VARR results they offered me a MUCH better outcome without the Formal Hearing. I think if you ask for an INFORMAL PEB appeal, it gives them an opportunity to brush off your concerns and give you a LOWER rating outcome.
Hope this helps...