For most use, I think the lighter Red Guns are the best choice. The lighter weight reduces injury, both from the flying object and in the retention drills. After you gain some skill, then either the Red Guns at full weight or the Blue guns are good. I personally do not like the color of the Blue guns because I also use the Simunitions Blue guns and I like to have an instant check that there are no live guns in use (yes, Sims are live guns). The few blue guns I have are painted red.

Respectfully,

Jerry