I am looking for the M5/M500. The timer as well as the extra brush seem worth it to me but I cannot find an (online) dealer. I contacted Maytronics and they referred me to using their website to find the closest brick'n'mortar. Not my preference but I guess I will cave if I have to. I also have an email out to Epic to see if they can order it.
If anybody found an online dealer I would love to hear which one. Otherwise, I physical pool store in Northern California would be helpful as well.