Count me in as a DG834GT fan too, though never had a D-Link.
When connected at 9dB target in daytime, mine usually dip to about 5dB in the evenings.
On that cycle of 9dB daytime dropping to 5dB in evenings, it holds onto the connection for weeks on end and when it does drop, it's usually for a good obvious reason like a power cut. My 24 hour average is probably about 250 Errored seconds, and maybe about 500 CRCs, which I'm happy with, and doesn't seem to upset BT's DLM either. Every line's different, of course, and you may find it's not so good on your line even if the reported SNRM is similar.
You also have to consider the device stability as well as the line-interface stability. For example, I had to dismiss a TG585V7 because although it seemed to cope better than the Netgear in terms of connections speed & SNRM, the darned thing just locked up solid several times a week needing cold reboot to get it going again. My DG834GT has been rock solid in that respect, too.
I'm running NG firmware. It's not that I disagree with HP, it's just that I've been too lazy to try the DGTeam, it may well make it even better.