You do hear that the engine rev up a bit quicker if you are observant, or at least if you look at the rev meter. Would be nice to have a led indicator on the dash when it's activated.
Just remind a funny anecdote with TT-Cup : A while ago I spontaneously entered an MP Race @J-F Chardon had joined and as I always had bad luck entering a race with some "celebrity" (Dev or Pro-Driver- mostly too late or just came from an exhausting race) I gave it a go last-minute. But , oh dear, as I preferably raced DTM 15 (due to wintercup competition) or in case GTR 3 I tremendously sucked, throwing my car in DTM 15 style into the corner - with J-F right behind me - well should I say more ? I like the TT's a lot (did one SP Champ a while ago) but if you're coming from fast series like modern DTM it's like trying to control a brick on an ice track.......so that was one of the rare opportunities I silently drove aside and quit without any comment (f****** embarassing)
I don't recommend to purchase from Steam, their prices are usually very high, get it from Allkeyshop or https://gameskeys.net, they compare prices of games.
After you have bought a few cars and tracks for iracing, everything is reasonable for raceroom no mater were you buy it.