How slow is Panasonic 20mm f1.7?

I was planning to purchase a micro 4/3 body (either an Oly EPL-3 or Panasonic GX1) along with a Panasonic 20mm f1.7 as a more portable complement to my Canon DSLR gear.  Though I'm not looking to replace the Canon gear yet, I would consider it if I fell in love and then maybe pick up a few more MFT lenses.  Main uses would be group portraits and kid-in-action shots.  I keep reading about the slow autofocus speed of this lens however.  My questions:

How slow is slow autofocus?  Is it slow by any standard, or does it still whip any point and shoot?  I am also considering Pany LX7 but think I may be disappointed by its depth of field abilities.  Would the LX7 beat the EPL-3 + 20mm f1.7 in terms of autofocus speed?  Finally, is there a speed advantage to matching a Panasonic body with Panasonic lens vs. Oly body with Pany lens?

Thanks in advance!