Hi and welcome to the forum.
My guess is that you have a
very long line, the Netgear won't report a larger attenuation above 63.5db. To have an upstream sync higher than your downstream suggests to me that there's a lot of noise being picked up on the line, probably between you and the exchange if you're in the test socket (I'm not sure whether you are or not). The noise margin is not hugely significant, it suggests to me that you had a resync at a noisy time, and the noise has lessened. 1.3db would certainly give you significantly more speed, relative to your current sync, probably 100-150kbps, but I have a feeling that, in return, you'd find the line less stable.
A 2700 has to be worth a try, for many of us on long lines, it's given a significant improvement in speed and stability. Another router to consider is the Billion 7800N, a tad expensive, but it has settings for long lines which are reputed to give a marked improvement. It's also future proof as it can be used with fibre should that ever be an option for you.
what is the best way to test and post stats from the test socket? still been unable to test my phone line using that site, it just errors on me like last night
Not sure what you mean. Are you uncertain of how to use the test socket or how to cut/paste the results?