I have had an E-PL5 for about 7 months.
In good light:
oly 14-42 mk II: very fast focus
Panny 12-32 pancake: very very fast focus
Oly 40-150: very fast
Panny 20mm: reasonable to fast. Faster than it was on my e-pl2
Bad light:
oly 14-42: reasonable
panny 12-32 pancake: reasonable
40-150: reasonable to slow
panny 20mm: Sometimes reasonable, other times its hunting season.
C-AF/Tracking just doesn't work at all very well.