So I've played a few rounds now with the E5 as opposed to the Srixon Q-Star I've played with for a while now.
First, these things are longer than the Q-Star. I'm about a half club longer w/ irons. Driving distance IDK because it's been real wet but I have to believe it's further there too.
These things definitely spin more around the greens. They stop quicker. This is what I wanted.... I ball that spins for under $30.
As for the feel of the things... They are definitely harder. You can take a wedge in your hand and just drop different types of golf balls onto it and listen to the sound it makes. The E6, for example, claims to be the "softest multi-layer ball on the market". It makes almost no sound, like a tennis ball. The E5 makes a higher pitched "click" sound. Q-Star somewhere between the two, same for ProV1, etc.
In summation, you get what you pay for. The E5 performs much like more expensive ball, but definitely feels kinda hard.