Use the powerline utility's - when the units are connected you should see the connectivity speed. I had a 200MB and a 500MB unit linked together - due to the distance my speed was showing at 70MBs...

Same thing happened to me with a PA210 flashed with PA211 firmware - my fault but no warning from the utility. Any clues as to other ways of firmware upgrades?

I just got a PA210 working with a PA551 by running the PA210 utility software and doing a factory default reset - that was the only way to get round it.