It's definitely much faster. I'll try everything new I get my hands into with diabetes and my treatment at the time was not that great, so it was pretty easy choice. First I did Fiasp when still with MDI and it's not that great to be honest. Even half a unit can be too much and it's very hard to dose if you don't use a proper bolus calculator.
Of course using it in pump is a different story, especially if you have a CGM with the pump. Right now I'm using the SMB algorithm in AAPS, that can help with unannounced meals by giving small boluses if it thinks you ate something. The same mechanism pretty much evens out my dawn phenomenon.
One thing you should know before trying Fiasp is the molecule size is much larger and might cause stinging feeling when the pump gives you dosage. Try to get a pump that goes slow with the dosing, otherwise the first couple of months might be a bit unpleasant. You'll get used to it though and I don't really notice it anymore.