I find the flavorings to be a little on the artificial tasting side. I used a 3# can of peach puree in a 5 gallon recipe and it came out really well for my peach ale. Peach on the nose and a taste of peach without being too overbearing.
I've also had (haven't actually made) homebrews made using frozen fruits taste really good. I just liked using the puree since it's all been done for you, and it's sanitary, rather than having to deal with it myself.
Pending on how much you want the flavor to show, a 3# can might be a lot, I feel like blueberries are kinda 'strong' at least stronger than peaches, in terms of taste.