I have used LCD Angels, LED Angels, Shockers, and almost every other electric gun on the market. Hands down, the Excalibur tops all of them. It shoots just as fast as you can pull the trigger. I will take a Excalibur over any free gun.
Currently, I don't own an Excalibur. I do however act as the Excalibur airsmith for my team's 11 Excaliburs. THere are no upgrades need for the Excal other than a good barrel. The Javelin is OK, but I prefer a Boomstick.
Again, no upgrades are needed other than a barrel. I do recommend a GOOD hopper. The Ricochet, HALO or other good loader is a must.
Everything is good. For those of you that prefer Cockers - this gun is a dream. All the action of a cocker in a electric gun. It even has a little bit of backblock like slap. Cool.
In early Excals, there were problems with the solenoids and the reg cores. All of these problems have been addressed and fixed.
I will recommend this gun to any paintball player that can afford it. Yes, it is a little expensive, but it is well worth it.