The G.INP / Vectoring beta firmware (r48494)? No, I used the Firmware 3.7.8.1 For ADSL/VDSL lines with Vectoring.
I didn't know that draytek had posted G.inp compatable firmware. I may give it a try sometime tomorrow, though I am quite satisfied with the current firmware.
I was about the first on my cab to have VDSL almost exactly a year ago (cab 17, Maesteg exchange, Huawei cabs). The BT line checker said my max download would be 33mbs, so I was pleased to sync at the full 40mbs, with a max obtainable of 49mbs. Of course as more lines were activated for VDSL my speeds fell to about 31 mps.
The draytek with the vectoring firmware gives me the best speeds, I also have a unlocked with the latest firmware huawei 612 and a install engineer supplied ECI modem. The 612 only gives me between 28-30 mbs so the vectoring makes a big difference.