I personally really like the Vitaflo PKU express coolers and Phenylade Chocolate. BUT as far as after-tastes go they do leave an after taste. I like the coolers because they’re very convienent since they come premade, but they have a very strong vitamin type of a taste. If your worried about the tastes have you thought about trying Nutricia’s Add-ins? You can add them into just about any food and as long as you don’t load your food with it you shouldn’t taste it nor should it taste gritty. I used to like the Phlexy-10 juice pouches to. I think I drank the tropical flavor. I stopped taking them though because if you left them sit for more then a few minutes the formula sank to the bottom . I thought the Phlexy-10 bars were pretty good as well and my 9-year-old sister who also has PKU likes them to. If you can’t tell I’ve gone through A LOT of formulas in the past 17 years! I hope this kind of helps, if not I’m sure I could think of AT LEAST five other formulas that I’ve tried at one point or another.