The only way is ........

[#1]

........ Down....
The move to ADSL2+ started very well. In the first few days my sync rate moved up to 15Mbps (following a few requests from PN to increase my profile). The line was steady, through put good, and Noise, etc good. So I was hoping for this to improve further - unfortunately not!
After returning from a business trip I discovered the sync had dropped to 9mbps and so far the PN profile dropped to 9000, then 8000 (yesterday) and 7500 today.
This morning the stats show:
ADSL Link Downstream Upstream
Connection Speed 9458 kbps 855 kbps
Line Attenuation 27.5 db 16.4 db
Noise Margin 12.5 db 6.0 db
I have an i-Plate fitted and a Netgear DG834GT running DGTEAM firmware 848. Ticket 29081768 has been raised
Any advice please....

[#2]

Update....  Profile remains unchanged... but out of the blue...
ADSL Link Downstream Upstream
Connection Speed 11081 kbps 855 kbps
Line Attenuation 27.5 db 16.4 db
Noise Margin 9.4 db 6.3 db

[#3]

How long have you been on the trial. It tends to take much longer than 10 days that Plusnet mention, for the line to stabilise (just under a month for myself)
I've also heard several other people complaining about performance with the GT model. It might be worth buying a cheap DG834 off ebay and seeing if theres any difference.

[#4]

Been on the Trial since 18th Sept...

[#5]

Means your still in the 10 day training period, it will settle down and become more stable,
Congratulations you have a pretty good quality phoneline.