Home Hub 3 with low sync speed

Question

 Excuse a newbie who's somewhat jealous of people complaining how they only get 8Mbps!
A combination of factors means that for months I have been getting a sync of 2624-3040, which equates to a profile of 2000-2500 and resultant download speeds of 1650-2250 using my old Voyager 2091. Then about a year ago, after fitting an I-plate etc. etc. I was achieving fairly consistent downloads at 2200 - so I asked for BT Vision. I can't comment on it, because almost immediately my download speed dropped and my profile was set back to 2000 so Vision was a waste of space. This didn't correct over time, so at the end of September I called up and an engineer came to test my line, swapped me to a new pair due to earthing issues and said I might want to replace my trusty old voyager. All this disruption still had negligible effect, so around Xmas I obtained a Home Hub 3.
Bad to worse - in the last week I have had to reboot the HH3 at least 5 times (so I'll never get to the end of my BRAS training period) and whereas before I could watch Iplayer etc. 95% of the time, now it seems incapable of streaming for more than half an hour, before the speed drops below an acceptable limit. I'm close to junking the HH3 and going back to the Voyager.
Is this normal? I've read about the HH3 dropping speeds on contention - am I seeing the issue because this makes my speed unusable? (A drop of 1Mb on an 8Mb speed might be annoying, but for me it's fatal!) or do I have a rogue hub .... in which case, what do I do?

Answer 1

Results fresh in as you'll see - internet froze again 20 minutes ago and forced ANOTHER reboot.
With regards to your standard questions - as you'll see from my earlier post, I had a BT engineer in with me for over 4 hours in September, so all the "normal" tests were done, internal wiring checked, quiet line test was done from the master socket, he even swapped me to a new pair with better earth. There are 3 extension and the NTE5, all filtered. .... oh and neighbours with another provider achieve 2K+ constantly.
I am not now connected to the NTE5, but the engineer cut the bell wire and it has an I-Plate anyway (belt & braces!). During tests with him and for 3 weeks after (without a reboot) the router was connected directly to the master socket and it made no difference, except weakening the wireless signal to my office. So I am again connected to my office extension socket, as before, and the move had no discernable effect on sync since October.
So I'm not really expecting much on sync,  live in a rural area, 2.5 clicks from the exchange (ADSL/POTS) but have a line length of over 4Km using the normal calcuation, probably with lovely aluminium along the way.
I'm just gobsmacked that the new Hub appears to be unfit for purpose, drops the download speed at the drop of a hat and freezes up on a regular basis .... so this is my final fling before jacking it and probably joining my neighbours with a provider who CAN offer an improvement.
ADSL Line Status
Connection Information
Line state:                               Connected
Connection time:                      0 days, 00:16:54
Downstream:                           2.625 Mbps
Upstream:                               448 Kbps
ADSL Settings
VPI/VCI:                                 0/38
Type:                                     PPPoA
Modulation:                             G.992.1 Annex A
Latency type:                          Interleaved
Noise margin (Down/Up):          6.4 dB / 18.0 dB
Line attenuation (Down/Up):     56.6 dB / 31.5 dB
Output power (Down/Up):        18.1 dBm / 11.9 dBm
FEC Events (Down/Up):             88308 / 2
CRC Events (Down/Up):             3197 / 7
Loss of Framing (Local/Remote):  0 / 0
Loss of Signal (Local/Remote):     0 / 0
Loss of Power (Local/Remote):    0 / 0
HEC Events (Down/Up):             1694 / 1
Error Seconds (Local/Remote):    544 / 3
Test Results
Test1 comprises of two tests
1. Best Effort Test:  .
Download speed achieved during the test was - 1752 Kbps
For your connection, the acceptable range of speeds  is 400-2000 Kbps.
Additional Information:
Your DSL Connection Rate :2688 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 2000 Kbps
2. Assured Rate Test: 
Download speed achieved during the test was - 747 Kbps
For your connection, the acceptable range of speeds  is 576-600 Kbps.
Additional Information:
Assured Rate IP profile on your line is - 600 Kbps