There are others here more knowledgeable .The higher attenuation is due to the increased frequency range in adsl2+. Whether this will reduce data throughput others will know, believe not.
Your attenuation will not change but snr could lower.
What is your data throughput using downloads in tools section here?

Not a long term silution, but try to get hold of a 2-wire 2700-HGV and run that for a few days. It has a lot of useful information within teh GUI and will help you see what you line is capable of and how it is performing.

From what I can see, you are performing a little worse than ideal - 7.4dB SNR/margin whereas a 6dB target will give a fraction more but during te day that margin will change possibly with a 2dB swing.

Let it all stabilise and see if te SNR drops ultimately to 3dB which will give a noticable increase. It may take two or three weeks before it does.

In reply to a post by Mr_Wonderful:

ATM with the line training I don't want to disturb it.

Yes its a good idea to leave it alone. I would be surprised if "Latency type:Fast" doesn't change to "Latency type:Interleaved" at some point, noted on the stats, after a resync...

In reply to a post by MHC:

Not a long term silution, but try to get hold of a 2-wire 2700-HGV and run that for a few days. It has a lot of useful information within teh GUI and will help you see what you line is capable of and how it is performing.

From what I can see, you are performing a little worse than ideal - 7.4dB SNR/margin whereas a 6dB target will give a fraction more but during te day that margin will change possibly with a 2dB swing.

Let it all stabilise and see if te SNR drops ultimately to 3dB which will give a noticable increase. It may take two or three weeks before it does.

+1 for the 2700-HGV (was it not supplied as a BT Business Hub at one stage)? Settled down to faster speeds than any other router I tried on ADSL.

In reply to a post by GonePostal:

+1 for the 2700-HGV (was it not supplied as a BT Business Hub at one stage)? Settled down to faster speeds than any other router I tried on ADSL.

Yes, they were the BT Business Hubs. I recently sent about 5 back to BT for recycling!

I have a scren shot taken where it had sync'd at 3dB then as noise changed over the day in kept sync at 0db and just below.

The DLM should still be active on my connection, it began earlier this week.
It re-synced during the early hours and the connection speeds have gone up a little bit (40 Kbps/540 Kbps) so it looks like the DLM is testing the line/connection to obtain the best speeds. The Signal attenuation is down slightly but probably due to normal variation.
Here are the latest from the router stats:

Product code:Smart Hub 2
Serial number:<REMOVED>
Firmware version:v0.27.06.04290-BT
Firmware updated:Fri Aug 13 15:38:43 2021
Board version:R01
GUI version:1.74 12_11_2020
DSL uptime:0 days,08 Hours17 Mins56 Secs
Data rate:832 Kbps / 6.135 Mbps
Maximum data rate:1.064 Mbps / 6.540 Mbps
Full Fibre (FTTP) Mode:Off
Noise margin:5.5 / 4.3
Line attenuation:24.7 / 48.0
Signal attenuation:0.0 / 51.8
VPI/VCI:0/38
Modulation:G.992.5(ADSL2+)
Latency type:Fast
Upstream error control:Off
Downstream error control:Off
Data sent / received:3.3 MB Uploaded / 18.6 MB Downloaded
Broadband username:<REMOVED>
BT Wi-fi:
2.4 GHz wireless network name:BT-C8CK5Q all disabled
2.4 GHz wireless channel:Smart (Channel1)
5 GHz wireless network name:BT-C8CK5Q
5 GHz wireless channel:Smart (Channel36)
Wireless security:WPA2 (Recommended)
Wireless mode:Mode 1
Firewall:On
MAC address:<REMOVED>
Software variant:-
Boot loader: 0.1.7-BT (Thu Nov 30 09:45:22 2017)

Incidentally, your sig is confusing . Sky?

I switched from Sky to BT in August and I have not updated my Sig. With everything so up in the air ATM everything apart from the ISP uncertain.

lol by the time this has been sorted out, ultra fast FTTP should be available as I was informed by Openreach on 15th July. The email claims that it would be available in 3 to 6 months. With Christmas & New Year so close that could mean early next year.

With your SNR figures there is not going to be much increase in upload download. The difference in speed is not going to any real difference in line throughput. You are still on fast line clean..
To be honest I would be happy with the figures you have, considering distance from exchange.
I did find that when Fibre was activated at exchange my maximum download sync reduced on ADSL.
After training you could try ADSL2 sync.
At least BT support has come good.

I support the view that ADSL2 is likely to be the best of the three options.