There was a time when I almost tossed my 505 in the trash becuase it just sat in a deep box of old gear and never saw the light of day for 10 years. But then I found a use for it as a way to record myself and clients when we didn't use a real drummer.
Over time I've used it many different ways including midi sync to my Atari.
Now I leave it plugged into the midi input/output of my interface and use it from time to time to determine the tempo of a song. Sonars tempo control requires a lot more fuss than the big knob of the 505. Once the tempo is determined you can then set Sonars tempo and use the midi output to sync the drum machine. Now the clock will be solid. The 505 drifts because of the static knob.
Not only that but I don't use the internal sounds. I just point the midi input at Session Drummer. This way you can also turn down part you don't need and say, just have a hi hat or kick.
So the result is a quick and easy drum machine pattern to help get a song going and without the annoying old school sounds. I just find it very convenient to work this way. I also find it faster to be able to switch patterns on the fly as the client plays until you find a good match for the song and they agree. My 505 is laid out in a logical way and I have it memorized.
Sometimes I then record the audio output to a track to use as a quick drum track to build on latter.