Hi JK,
Rik will explain better, but I think the thing with the AR7 chipset is over-hyped, as plenty of people use them with no adverse effects. Obviously, though, we can't guarantee that there are no problems with your particular router.
The advice from IDNet is worth taking. They have had many, many customers who have come over from Pipex / Tiscali, and have experienced a much better service. Of course, there's no cast iron guarantee of how your line will behave when on MAX, and occasionally there are issues in the BT realm, which are beyond the control of IDNet, but they do have very good contacts within BT and can usually sort out most problems, if they arise.
If you refer to Rik's post earlier in the thread, this gives an indication of the speed you are likely to achieve on a MAX service. If in doubt, give IDNet another call and talk it through with them, as they would be more qualified to deal with the ifs, buts, and maybes. We can only advise here, on previous experiences.
Hi JK
Max is a rate-adaptive service, [in other words], it will try and go as fast as your line can support. The single most critical factor in that is your downstream attenuation, which for you is 39db. At that level, I'd expect you to be achieving a sync speed of 5-6000kbps. The other factor though is the quality of the line and its susceptibility to noise, and that's much harder to quantify. I sync at around 3500 on a 56db attenuation. My neighbours sync at between 512k and 2000k, the attenuation figures are similar within +/-2db.
Normally, BT give you a target noise margin of 6db, and run the line as fast as possible with the margin. In your case, it looks like the dynamic line management software has found your line unstable at that speed and so increased the target margin to 9db. That will cost you about 500k of sync speed.
A shielded ADSL cable (RJ11-RJ11) may help, but the reason I suggested borrowing another router is that different makes work better with different lines, with a possible speed difference of 1000kbps or so. It also eliminates any possible fault with the router.
As Simon has said, you shouldn't have to re-train with a like-for-like migration. There is no fixed-rate 4Mbps service though, the fastest fixed rate product is 2Mbps.
You're very welcome to join IDNetters, as is everyone, but I'll always try to answer any questions here. Obviously, though I spend most of my time over there.
HTH
