...But let's compare like with like...
If you cooked at the exact same temperature with charcoal as with gas, and if you didn't use wood chips/chunks in the coals (and no smoker pouch for the gas) and let's also assume we are cooking on a grate that is brand new and unseasoned for both, do you really think you would be able to taste the difference between the two?
As a side note, you can get a "kiss of smoke" with a gasser too. I used to smoke all the time with my gasser (when it was the only cooker I had) by putting wood chips in a foil pouch and poking holes in it. Sure, smoking is easier with a charcoal grill, particularly for long cooks. Yes, for high heat cooks, my gasser gets nowhere near as hot as charcoal (and for that matter, it is much easier to cook LnS on a OTG than on my Brinkmann), but if you have a gasser capable of the same high heat as a charcoal grill and hold the other variables constant, I doubt any but the most refined palates (which doesn't include me) can detect the difference.
22" OTG; 22" Performer; mini-WSM; Brinkmann gasser; UDS (on the way); Maverick ET-732