In fact, even being considered a baseliner, Borg came to the net more often during a match than Nadal or Djokovic during a year.
I actually think Nadal is a better volleyer than Borg was, and Djokovic might be also. Borg came to the net more, especially during Wimbledon, but that was during a different time with different equipment. Back then, if you hit a deep approach and made the other guy run, it was actually tough for him to hit a passing shot. Now the pros can pass from almost any position.