Trying to work out the extra SNRM of 0.8db on my line that works out at close to 2Mbps that works out at 61995 Kbps now if you say G.INP gave you an extra 5Mbps then 61995 + 5000 = 66995 kbps
Also G.INP can take 7 weeks to be turned back on after line reset or change of provider from what I can see in this forum
PS my SNRM mathematics may be off but WWWombat will give your correct results if he is about.
I'm on holiday, so don't have my cheat tables with me. IIRC, 3dB is worth 11Mbps to someone with access to the full spectrum (likely syncing 70-80Mbps). I guess 0.8dB would be worth about 3Mbps.
Note that when G.INP was added to my line, the attainable went up (IIRC) nearly 10Mbps (97 -> 107). Remember this is a line that was already fastpath and synced at 80/20, with around 60 ES/day. There was no FEC overhead, so the (small amount of) overhead added by retransmission ought to be a negative impact of around 4Mbps, though it did take me to zero ES/day.
From my experience, I'd accept that gazaai's line is capable of jumping to 68Mbps, with its own perception of what other coding gains have been gained.
I also don't have access to the graph of speed improvements gained with G.INP (from BTW?), but it is certainly the case that not all of the improvement can be explained by just those lines losing the old-style FEC+interleaving setup. G.INP did more ... something less tangible.