Would the Mantis be ideal for dueling if any of my duel-willing friends want to go heavy or if I get into the dueling community or is it more of a show-off trick saber that is better for light combat but not full duels?
Personal Opinion: Neither. If you're expecting it to be the slim, agile Count Dooku hilt, it's not. Due to space requirements for electronics and such, it's a much bigger, bulkier saber. Due to the bend, I don't find it comfortable to use with two hands, and about the only place I can grip it to use it one handed is right at the bend, and it just doesn't move right in my hand. Weight wise, it's not any worse than any of the other US sabers, so it can easily be used with one hand and a heavy grade blade. I'm just not a fan of the curved hilt.
As far as weight in general, all of the US sabers are aluminum, so despite their size, they weigh surprisingly little. Someone asked in another thread how fast you can swing a US saber, to which the best answer is "how fast can you move your arm?"