Mr.Gadd is right, considering Mr. Lang & Mr. Donati would also probably refer to him as Mr. Gadd.
Mr. Gadd was easily THE MOST 'in demand' session player in the history of the instrument. By a long, long,shot.The guy coming in second wasnt even close.
He was the Michael Jordan of drums
Everyone wanted him on their record, from folksy ol' Paul Simon, to Jazzy Chick Corea, to fusioneque Steely Dan, to name a few.
Now that should tell us something about about what people are looking for in a drummer.
Without getting into the groove v/s chops debate, which is the silliest thing drummers can possibly talk about IMO, may I recommend that you listen to Mr. Gadd's solo on Steely Dan's Aja, and his playing on Chick Corea's Leprechaun, to get a taste of what he can do when hes not plain grooving.