I believe that Lazar Berman's performances are very spirited, yet true to the intent of the composer, as here with Rachmaninoff. Berman really thunders out the octaves, while playing the quiet lyrical parts with delicacy and refinement. I was fortunate enough back in the 70's and 80's to attend several of his recitals and concerts.
If Corelli was the first to identify this ancient theme and apply it to his own works, then there is no harm in calling it "Corelli variations: The theme is beautifully applied here by Rachmaninoff as it had been done some years earlier by Liszt. Berman has a typically Russian approach to this work, and is among the best recorded.
This interpretation by Berman sounds natural and effortless compared to other renderings. The product, I suppose, of practice, practice, practice, rejecting the tenth or twentieth take and discovering the the arc, the shape of the whole set. So that, as the echo of the last chord of the final variation still lingers, the first note of the coda is the great hinge after which all the melodic and rhythmic tension is unwound.