I've been with Sky Broadband (the "Max" service, up to 16mbps) since early Feb.
Had
Firefly ADSL (fixed 2mbps) for the preceding 12 months, & before that had ntl cable broadband for around 5 years (moved to a non-cable area Jan. 2006).
On switching to Sky, I initially only got around 4-5 mbps IIRC.
This was, however, due to factors unrelated to Sky which would've affected my connection regardless, had I been with any other ADSL ISP offering more than 2mbps via LLU or ADSLMax: Attenuation & Noise Margin.
Couldn't do anything about attenuation, obviously, but at the
suggestion of Chrysalis I was able to improve the noise margin by removing the ring wire.
More here:
Sky BB speed issues - improving a poor noise margin
This saw my speed jump to around 8mbps. I've since made further improvements (to stability & error levels, more so than speed) by fitting an
ADSL Nation XTE-2005 filtered faceplate, & also rewiring the extension sockets.
I was initially connected using Sky's version of G.DMT, on Interleave mode, with a download speed cap of 8096kbps.
I've since had it changed to ADSL2+, Fast Path mode, with no speed cap.
Although my attenuation & noise mean I still don't tend to get any more speed than what I previously got on G.DMT, being on Fast Path rather than Interleave gives me better pings, which is good for my Xbox Live.
Like downquark1, I've found a lot of help & useful info at SkyUser.
Based upon posts at SkyUser, I've turned off UPnP on my Sky router, which seems to have sorted some initial disconnection issues.
I did still have some other router issues though at first... the router would automatically reboot itself quite regularly.. which was quite a pain.
After some playing around, I now have it sorted. Seems that, like many other routers, it can get a bit overwhelmed if you do a lot of P2P e.g. Torrenting.
Cutting the speed & connections in my bit torrent client have cured the reboot problem completely. It now stays up for days/weeks, rather than having a fit every hour or so.
Two very handy links regarding router stats, attenuation, noise margin, error levels:
Sky router stats (speed, noise, attenuation) explained
How to obtain detailed stats, & interpreting line errors
downquark1 has already mentioned "Mognut's" very useful "
Sky Netgear DG834GT Utility".
I use an alternative app, which runs in the system tray, rather than being a web page like Mognut's utility.
mossywell's "Bounce Sky Router"
Bounce monitors the internet connection, & automatically sends a reboot command to the router if the connection goes.
It can also auto-reboot the router if the noise margin drops too low (to a user-defined value), & can be used to send custom commands to the router, such as to tell it to re-sync at a particular noise margin.
It also lets you view the detailed stats, & extract the ADSL username & password.
My main issue (noise) was nothing to do with Sky. The router was initially flaky, but is perfectly fine now. Pity they don't let you use other routers (well, you can, but it's against the Terms & Conditions), although I guess it helps simplify support if the CS/TS people know everyone should be using a specific router.
I'm happy with my connection, the speed, the stability, & especially the price.