I'd say it really depends on the last time Vegeta and the Freeza scrubs had last interacted.
The timeline starts, at the very least, from when the decision was made to send Raditz to Earth.
So, basically, the proposal is that the Saiyans have a few [mis]adventures, at least one of which was too much to handle... leading to Vegeta gaining a little strength from his "ceaseless" battles. +1,500 over the course of a few years doesn't seem so much... and still leaves Earth's zenkai and technique acquirement as the only one worth highlighting.