I noticed in the movie that the crossgaurd lightsaber did have a purpose as I had expected.
Ren basically presses the crossgaurd edge into Finns shoulder while there sabers were pressed against each other. Good enough for me for the practicality of it.
Also thought it was cool how the Sabers were evaporating snow during the fight scene
A few factoids about the Crossguard saber, from TVD:
http://i.imgur.com/sW56wXz.png
http://i.imgur.com/b9G4Qj3.png
In a nutshell: because the saber's kyber crystal is fractured, the purpose of the quillons is to shunt power away from the primary blade in order to help stabilize it... Kind of cool that the quillons serve a legitimate mechanical/functional purpose as well. 👆
That crossguard lightsaber looks like it would be horribly unbalanced. Probably heavy too, as it looks like a lump of iron.
With the crossguard, plus shape of the hilt, it would probably restrict wrist movements to the point of making deflection unfeasable. And being stuck hacking away like a meat cleaver is a huge disadvantage when a lighter, more practical weapon does exactly the same amount of damage, while allowing greater range of movement.
Not that I'm an expert on dualing, but just a few observations. It's no wonder Rey and Finn could hold him off, using that thing..
