It may be that you seldom see it for several reasons
1) Line condition
Its usually its only the good lines that opt for annex-m, after considering the downstream/upstream trade-off.
Be wouldnt let you have annex-m until they knew that the line could handle it. iirc it was something like 40-45dB atten when it was considered viable.
Good & short adsl2+ lines are far less likely to have line faults and in need of BT engineers. In over 10yrs of adsl, last year was the first time I had to have engineer visits.
2) Cost
With Be it wasnt that much more £ for annex-m. In fact if you were on Be Pro it was included in the cost. It was a no brainer for me to go to Be where I could get 24/2.6Mbps @ £22 pm, when I was paying something like £21.99 for 8Mb adslmax + £5 for maxpremium.
BTr originally only rolled it out to their business customers and at rather a large premium cost. Even though it is now available to consumers, its still a hefty extra which your average joe bloggs may not feel is worth it. I dont know how much BT are charging for it, but iirc its an additional £10+VAT at Plusnet.
3) Public awareness
Its usually only the more techie users who are aware of it, average Joe Bloggs who wants a dsl connection for £6 just wouldnt be interested in paying upwards of £10 more to swap some downstream for upstream. Those that did want it usually ended up at Be... and lets be honest which 'man in the street' ever really heard of them? It may be a wee bit more popular on now on BTw systems, as Ive seen a few ex-Be members having to stump up extra for the BTw version, rather than go with Sky.
