Two 12-60 four thirds to MFT. 2 questions - speed of focus & adapter

Considering the 12-60 2.8-4.

1. Focusing on MFT is slow.  Question - about how slow subjectively?  A lot slower than the 20 1.7?  Talking about OMD or PL5 body usage.

2. are all adapters basically the same or should one get the Olympus version? Thinking seeing if there's any 3rd party on ebay.

Thanks,

MTMT