This post is compile from a mixture of personal experience and information sourced from
Sky User support forum (not and official sky support forum)
Personal Background
My direct family have been cable customers for many years through the incarnations of
NYNEX,
cable and wireless,
NTLand now
virgin media. The last internet package we had with them was the 4mb (which has started off as the 512Kb if I recall correctly).
The change came around since a decision to renovate my step-father's house and move into that. He was using zen internet at the time (512KB @£24/month) and is not in a cable area.
Choosing ADSL ISP
Although
zen are highly reliable, have excellent support, their packages are relatively expensive and have enforced caps. Also have yet to have
unbundled my
exchange or support ADSL2+.
Investigating the sky website showed I could get 16mb BB and a basic TV package for a price comparable to what zen had still been charging for 512KB (as you can imagine I'm a bit ****ed they didn't offer an upgrade or at least lower the price).
Being relatively close to the exchange and having some technical knowledge and support forum help

I decided go try sky.
The router/modem
Sky provide you with a free wireless Netgear DG834GT. They do NOT provide you with your PPoA login name or password. This is hard coded into their modem they send you. Their terms and conditions state you must use their modem/router.
The router has custom sky firmware installed which hides your PPoA details but allows configuration to the wireless network, DHCP, UPnP etc.
The router is set to sync at a minimum noise margin of about 7db. The connection tends to be lost or drop out at 6db. The minimum can be altered (see hacking the router).
The UPnP feature has been reported to cause problems with different aspects of the router when active. Although I have no evidence for this I disabled it anyway.
Testing the wireless connection transferring a large file from a wired tower to a wirelessly connected laptop within a few metres of the router resulting in about 50% of the 54Mbps connection being utilised (I have no idea if this is good could someone please post).
"Hacking the router"
By means of special utilities provided by users at
Sky User support forum you can extract your PPPoA details and use another modem on your sky connection. This however is a violation of the T&C.
The routers connection stats can also be extracted and the target noise margin can be altered
Mognut’s Utility
Accessing and interpreting stats
Initial problems - ADSL2+ and noise sensitivity
The router would sync between 11Mbps and 14Mbps despite having good enough attenuation for the full 16Mps
Code:
Attenuation.............Approximate Line Length............Potential Connection Speed
32db...................................2.3km.....................................16000kbps
35db...................................2.5km.....................................14500kbps
40db...................................2.9km.....................................11800kbps
45db...................................3.2km.......................................8500kbps
50db...................................3.6km.......................................6500kbps
55db...................................4.0km.......................................4500kbps
60db...................................4.3km.......................................3200kbps
65db...................................4.7km.......................................2000kbps
The connection was fine for a few weeks but would sometimes drop to terribly low speeds. Upon inspection the noise margin was dropping at night and the connection was getting significant error spikes.
At the advice of
Matt D I installed a
XTE-2005 face plate on my master socket and disconnected the ring wire on my extension.
The setup looks as follows
(ROUTER) == unfiltered extension == (XTE-2005 master socket) ----filtered extension --- (phone)
The difference was significant, it now syncs at the full 16Mbps with a noise margin from 8 to 10. The line remains virtually error free during the day. There remain significant error spikes at night suggesting interference from an electrical device however I currently believe it must be something outside of my control.
Pings and latency
Its my understanding that ADSL can operate in "fast track" mode or interleave. Fast track providing lower pings and interleave providing greater stability.
Based on sources from the
skyuser forum it seems sky's policy is to use interleave and will NOT change you if you request it.
I happen to be on fast track for whatever reason and get pings ranging from 39ms to 55ms. (Compared to 15-25ms on zen) Using traceroutes suggests most of the latency is on 1st hop after the router.
People report pings on interleave mode to be 70+. Some report that they managed to get sky to
lower it, other report that sky find it acceptable and won't fix it.
Sky's DNS server
Sky's DNS servers are quite laggy and sometimes report false negatives. I've switched to
Open DNS which is a large improvement.
Email reliability
Sky offer multiple pop3 email address. I set mine up no problem manually (i refuse to use BB installers whenever possible).
The outgoing SMTP has dropped out a few times, had no problems with the incoming as far as I know.
My conclusions
The connection is now in a state where I'm happy with it. Considering the alterations and the fact I am close to the exchange, I can only imagine the problems people further from the exchange are having who lack the knowledge or contacts.
I believe ADSL2+ is quite a flawed 'product' to present to the consumer given current network limitations in comparison to cable. And they should probably install filtered faceplates on extended lines as standard since the difference can be so significant.
As for SKY BB. If you are a avid gamer you may want to stay clear as you good end up with bad pings and an uncooperative sky support.
These days with such high bandwidths I think the DNS lookups and latencies are going to be causing more overhead when viewing simple websites.
Sky's insistence on using there own router may offer a few problems for some people, some have reported getting better stability going against the rules and using their own router.
For the price the bandwidth is extremely tempting but you could find yourself working hard to get the most out it.