There were a few pilots who flew actively in both wars, and many other pilots who flew combat in WW1 and undertook non-operational flying in WW2. Theodore Osterkamp is probably the most famous.

Of course, many leaders in the Second World War flew fighters in the First: Dowding, Udet, Sholto Douglas and Goering. I am not aware of any who reflected on the changes to aircraft specifically, though for those who remained close to aviation they would have experienced the continuous development of the aeroplane, rather than experiencing the change as a 'step'.

Another thing to bear in mind is that even from 1916 to 1918 aircraft developed considerably. Most planes of 1916 would fall apart of manoeuvered aggressively, struggled to 10,000 feet and lost that altitude quickly, and had very unreliable engines. By 1918 aircraft were much more airworthy and reliable, and of course the air space was far, far busier.

If you are interested in pursuing the matter, Ernst Udet was heavily involved in aviation from 1917 until well into World War II