My teacher has recommended that I do that on occasion. One time, the purpose was to take an interpretation I liked of the piece I was working on and as I played along, notice where the player moved the music forward and where he took some time. This gave me a better understanding of what he was doing that drew me to the interpretation. If there was something I really liked, I might incorporate it into my own interpretation...but what I played was still my own interpretation.
Another time, not playing along, but conducting by counting to different people playing the Sarabande of Bach's 1st Cello Suite, both guitar and Cello, and noting the time they were taking in their phrasing. All of the players were scholars of Bach's music, some recordings were 25 years older than other recordings, so the way they played also showed how the understanding of his music had changed over time.
In all cases, I've done this only after I know the piece fluently, so it is meant to deepen understanding after being able to play the piece in strict time.
When the sun shines, bask.
Classical Guitar forever!