I believe on Seattle Coffee Gear they did some testing of that on commercial brewers and they said they couldn't tell a difference. It's not a commercial machine but I have a Bonvita 1900 which has pulse brew (no pre-infusion) and normal brew mode. They taste pretty much the same. I do pulse brew though because when I put my freshly roasted coffee in there it sometimes overflows if I am brewing a whole pot and if I pulse brew it has time to bloom.
