Well, the hub has been up for over two days now, and no apparent slowdowns, at least not when I've been using it.

Speed has been a rather less than spectacular 44Mbps, but maybe that will improve if the hub stays up?

Anyway, Plusnet take over later this week. Will see what happens then (if anything).

Have been on Plusnet for exactly a week now. The hub has reset/restarted itself a couple of times, most recently at around 1500 today. Up until then, I'd been getting 66Mbps without any slowdowns (though I've not been in during the day). And now... just under 70Mbps!

Of course, it could still all end in tears. But for now, I'm very happy, and curious why a change from (effectively) one part of BT to another should have had such a beneficial effect!

A Plusnet hub, or your old BT one? (Which was possibly the problem).

That could account for the improvement.

Edited by RobertoS (Wed 05-Apr-17 22:34:41)

Still the old BT HH5!

Current stats are:

3. Firmware version: Software version 4.7.5.1.83.8.222.1.1 (Type A) Last updated 22/02/16
4. Board version: BT Hub 5A
5. DSL uptime: 0 days, 08:48:39
6. Data rate: 19999 / 75000
7. Maximum data rate: 22709 / 75196
8. Noise margin: 7.3 / 6.0
9. Line attenuation: 19.0 / 15.3
10. Signal attenuation: 18.7 / 15.5

And this was the last BT day (28 March):

3. Firmware version: Software version 4.7.5.1.83.8.222.1.1 (Type A) Last updated 21/02/16
4. Board version: BT Hub 5A
5. DSL uptime: 0 days, 16:24:05
6. Data rate: 19978 / 59926
7. Maximum data rate: 23854 / 73728
8. Noise margin: 7.3 / 9.8
9. Line attenuation: 18.8 / 15.1
10. Signal attenuation: 18.6 / 15.3

Noise margin DS is 9.8 on BT and 6 on PlusNet that is why the increase in speed. DLM reset? Look at the Attainable figures for both almost identical, but different target SNRm.

Looks like a DLM reset, but we need to see if the OP can do one manual power cycle of the Hub to see if the downstream rate isn't banded.