As Dante bridged the medieval and modern world, so did Beethoven the worlds of classical and romantic music. He has one foot firmly in each. In some ways you can view interpretations of any of his works as favoring one leg or the other. My first exposure to it was from an LP my father had in his collection. I have that in my personal collections of recordings and it was one of the discs I considered in writing this essay.
Lines are ever so slightly more tightly drawn, the sound is dryer, the tempi just a shade faster.
The sound of the piano is richer, fuller, has more body and resonance. The performance is certainly NOT laid back, but it is more mellow, more romantic a tilt. Frankly, I do not think that Firkusny was ever capable of anything less than a poetic performance, even when at his most dramatic, as in this concerto. If you have not heard Firkusny, this disc would be a marvelous introduction. The sound here is significantly better.