Netgear DGN1000 (N150) vs TG582n

[#1]

is the netgear N150 DGN1000 much better than the TG582n?

[#2]

I don't use either, but there are some difference in the specifications. If the 582n were given those ridiculous marketing wireless numbers, it would be N300. In practice, the DGN1000 wireless would be up to 65 or 72 Mbps, the 582n is up to 130 Mbps.
I think the DGN1000 is based on an Infineon (now Lantiq) chipset, the 582n is Broadcom, so ADSL performance could be slightly different.

[#3]

Based on reports of the 582n here, I would say they are both reasonable door-stops 
I have a TP-Link TD8816 and a PlusNet branded 585v7 and, in terms of ADSL performance/reliability, the DGN100 doesn't get anywhere near these two