Update...
Went for a tune again last night, on a different road. Much improved! This time I was listening for the cut-over as you suggested. It was there, just not as neck-snapping as I expected. The car really gets up to speed in 3rd gear
Still have the idling problem where after about 2 mins of idle, it would start "hunting" (similar to a turbo car) and eventually cut out. Tuner suggested I clean the idle control valve, so will do that today.
The difference between this tune and last was that with the last tune I was not able to hold WOT for a significantly long time, and the new road was smoother (and dead straight). Also I was shifting early, and the old road was not long enough for me to get lift in 1,2,3,4.
I guess I was assuming that the lift would lick in aggressively, so I was feeling like it wasn't there. Our drag club has a practice session on Saturday, so will give you some more feedback then. With the 1/8 mile drag I barely manage to change to 3rd though. If we get out 1000ft track then the car would be quicker!