Depends on what you'd consider as noticeable. I've got a SATA SSD as my boot drive and it also runs one Steam related game. My system boots up in about 30 seconds, fast enough for me to start it during a phone call for being able to walk a customer through some procedure step by step, being able to see the same view.
Said game is a slow loader for all my friends. On a HDD the actual game had often started before I could see anything, on this SSD I can hear other players running in the waiting area for a few seconds before getting there myself but I'll still have plenty of time to see the map and discuss the strategy before the actual game launches.
So although there may be a noticeable difference in boot or game loading times, we're talking about mere seconds. I'm old and slow so there's no need for me to snip those seconds off. Your mileage may vary.