We us both (as well as Xenith) I don't see a whole lot of difference in the two other than the Schutt helmets tend to pop of more frequently. I like to have a variety of brands because they all fit differently. I will say that the players all want the Riddell helmets, but the ones that have worn both say the Xenith fits the best.
We use the Riddell Speed and the Schutts. The kids want the Speeds because they think they're sexier. Most of the skill positions get the Speed and most of the hogs end up with the Schutts. The kids say that the Riddell helmets are more comfortable. I haven't noticed a difference in concussions.