I have a 2.0 S1 Esprit and I have driven a friends S1 fitted with a 2.2 (freshly rebuilt engine); both cars back to back and there really isn't much in it, he said the only difference is in torque but the 0-60 time would be the same if they had the same gear box.
I'm about to go to a 2.2 engine as it's what is available and the later engines are a bit more reliable due to the manufacturing improvements. I think you may find the 2.2 had a different gear set so the ratios made it seem quicker to 60 as there is 1 less gear shift, which would account for the press reviews.
It was the addition of the Turbo that made the big difference with the Esprit.
The power available earlier is the weak part of turbo charging, so I see why you are enjoying the NA for it's different performance characteristics but for me I like the tunability of the SE as I am not really enthusiastic about modifying engine internals. You can get 200 bhp easily with the Elan without adding lag or doing anything to the engine.
They could have built a lighter Elan, which would be nice.