+1, they lay better into the keystone jacks (we use PDL) going B spec.

Side note:

A while ago we had an issue using a cheap HDMI extender over Cat5e (customer suipplied), the picture would drop intermittently in a clients Bedroom and the run was only 10 meters (32.8 feet in the old language) from the HDMI Matrix. The cable spec was A, so first we changed the connectors on both ends to make sure it was not a faulty plug, we then run the HDMI extender directly into the source, bypassing the Matrix, but....the issue was still present and we where lucky enough that it was visible pretty well much straight away. At the time we had a specialized data guy working side by side on another project and he mentioned to us to go B spec, so for "sh#ts and giggles" we did. We waited around 3/4 of an hour and had no dropouts so we put the job under observation with the intent of returning with a new extender. I called the client back the following day to discuss prices and a return date and they said that they had not had a dropout yet......so I called a week later and they had not had a drop out at all, they where very pleased we had fixed their issue without the need of purchasing a higher spec extender.

Now it could of been 3rd time lucky on the termination of the plugs, but the IT guy did mention that the twists had alot to do with them going B spec as there was less interference inducted into the pairs giving more stability...or something like that :) All I know is that I have been going Cat6 B spec since then for all DATA and we have had no problems yet, touch wood.