Unfortunately my master socket is behind a heavy cupboard which needs emptying to move it. I have now had severe complaints
re leaving the cupboard away from the wall, the room full of the contents, and possibly marking the carpet. I have therefore done another swap test before putting it all back with the mark 3. I won't be swapping as much as I planned to.
I just briefly went back to the mark 2 and then returned to the mark 3. The attainable increase of about 1 Mb/s with the mark 3 occurred again so I am tending to believe it.
Judging from the previously posts bit loading's this improvement may only occur if your attainable is above about 60Mb/s and your using the highest frequency 17a tones.
The error rate over 24 hours with the mark 3 continued, from a couple of hours, to be about 30% less than the smallest normal 24 hour average, but as suggested by NewtronStar, I am sure a longer test is needed to judge error rates. I will now do a 7 day test with the Billion and then one with an HG612 as I am used to the error rates with both of those so a rough evaluation may be possible if thunderstorms allow!