BT Infinity 1 versus 2 on long line

I have BT Infinity 2, distance from cabinet is just over 1 mile.
Estimated download speed is 25Mbs down, 5.7Mbs up.
Actual is around 10Mbs download, 1 Mbs upload.

Does Infinity 2 speed drop off more quickly than Infinity 1 over long lines?
Would I be better off in terms of speed/reliability with Infinity 1?

As the technology is the same your speeds under Infinity 1 should be the same as Infinity 2 but you would save yourself some money.

So are there no technical differences in infinity 1 versus 2?
This implies a 40/10 service is just a capped 80/20 service.
If not achieving at least 40/10 then having an 80/20 service would be technically pointless. Is this correct?

Correct. there is no technical difference.

In fact 80/20 is also a capped service as an unrestricted could achieve 120Mbps downstream and maybe well over 30 upstream (depending on band plan).

Yes, your having an 80/20 is pointless - so go down to Inf1 and save money.

If your line is really a mile long, then you should never have been sold Infinity 2 as it would never be able to have got over 40mbps. I would go back to BT retail and get your product changed to save some money.

Incidentally, as you are some way off the estimate (which itself sounds optimistic for a line of a mile long), then have you checked this under optimal conditions with any extensions disconnected. This means connecting to the test socket (accessed by unscrewing the faceplate). Even if you don't have a power socket close to the master socket, it's worth using an extension cable temporarily just to establish a "best case" baseline. If this is a lot better, then it's worth reviewing optimising the domestic extension wiring, filtering and so on.

Also, it would be very useful to have the line stats (especially upstream/downstream sync rates, attenuation and noise margin).

In house cabling is best case with Huawei modem connected to master socket, so not sure if all stats available.
Line speed had been higher, now deteriorated, but up/down IP profile looks strange.

BTW test results:

Download speed achieved during the test was - 4.5 Mbps
For your connection, the acceptable range of speeds is 3.82 Mbps-4.77 Mbps .
Additional Information:
IP Profile for your line is - 4.77 Mbps
Upload speed achieved during the test was - 0.96Mbps
Additional Information:
Upstream Rate IP profile on your line is - 20 Mbps

OK. It sounds like home wiring is optimal.

Those stats look dreadful for any form of FTTC. Many people have ADSL2 better than that. Unfortunately, unless you have an unlocked modem then I don't think you can get the line stats. It might be worth contacting BT if there's been a serious deterioration.

Of course if the cable is actually a mile long it's never going to be good, but that looks awful. I know there will have been more cross-talk as take-up increases, but without knowing what it was before, I can't easily tell what's happening. If it is cross-talk, then the only obvious hope is for if/when vectoring is finally implemented.

Sounds like a good case for 'ADSL from the CAB' ! .

Ask BT if it's available yet.

Check your distance from the cab to your house with this tool.
http://www.freemaptools.com/measure-distance.htm

The "up" profile always tells you the capped speed for the line, and has nothing to do with the actual sync speed. The "down" profile, on the other hand, is directly related to the sync speed - but approximately 3% lower.

That means the sync speed is dreadful compared to your estimate in the original post.

What are the two ranges of speeds when you put your number in here?
http://www.dslchecker.bt.com/

The best advice now depends on how much you want to fiddle yourself, or whether you wish to leave it all to an engineer. On the first path, you'd unlock your modem, and start monitoring the line statistics. On the second path, you'd report the dire speeds to BT.

Dslchecker results
High Low High Low

FTTC Range A (Clean) 34.7 25 7.4 5.7 -- Available
FTTC Range B (Impacted) 27.3 14 7.1 3.3. -- Available

BT Hub5 after reboot ( direct with huawei modem removed)

3. Firmware version: v0.07.03.0814-BT (Type B) Last updated 24/2/2015
4. Board version: 01
5. VDSL uptime: 0 days, 03:22:53
6. Data Rate: 1233 / 11967
7. Maximum Data Rate: 1229 / 14507
8. Noise Margin: 6.2 / 6.5
9. Line Attenuation: 0.0 / 33.1
10. Signal Attenuation: 0.0 / 0.0