Well as far as I can associate with the O2 sensor yes... Car has gremlins, I'm missing about 100rwhp and 500rpm of response, but can't see that relating to the o2 sensor. Still searching for an answer to that problem. I also get a lot of reverberation, but again that is to be expected having an AFM in front of a big turbo.
As for the 'surging', that doesn't really describe it. It's not like a fuel surge you get from running low on fuel. It's like when I'm cruising on decel, using the engine speed to maintain roadspeed going down a hill or something like that, it sort of feels like I'm tapping the brake slightly and then taking it off. It slows down a tiny bit then picks back up. If I touch the accelerator at all then it doesn't do it. Given it only does it when cold, I imagine it is sensor related. Can only think of either TPS or o2 sensor, and seeing as my o2 sensor is unplugged then it makes sense.
/long winded explanation