I have used DC researchers for years for pension records. Cost is less than NARA and papers usually received within 2 weeks.
I have waited as long as 8 months for records from NARA, even after calling them!
Had to hire a professional genealogist to find my ancestor's Medal of Honor information because NARA couldn't find them! It was well worth the high cost for a pro, because I received many letters written by ancestor, including a narative of his experiences with Indians on the western frontier and a letter of recomendation by Col. Nelson Miles for his MOH.