Along with the new handle (based on a glock) I also gave it small iron-sights on the top. Because, anyone who knows weapons, knows you NEED iron-sights.
Also, I was trying to rationalize the design, make sense of what I saw and why it was there.
On my design, the metal grill between the two tips and the silver fins on the back are heat-sinks.
The blue tip is a focusing crystal, which refines the phaser beam. The red tip is an amplification matrix. You can change the power setting on the top as well as change the tip for extra power.
The highest setting of the blue tip is strong enough to heavily stun most humanoids. The red tip can vaporize rock, however it overheats REALLY quickly. Unlike typical phasers, it's not a constant beam, it's more like a very rapid pulse. The red tip takes longer to build up a charge for each shot, which is why it is typically only used for rocks, buildings, etc. The blue tip is much more practical in most combat situations.
The reason the two tips are placed the way the are is because of how the beam is created, this image will demonstrate: