For a 4 foot span of 600 to 750 sq inch area, there is a "sweet spot" of 4.5 lbs. At this weight, you can put your plane into the hands of the unitiated, and with reduced control throws, it's difficult to tell it's not a trainer.

As the weight goes to 5 lbs and over, it loses it's niceness, but in the hands of good flyers, this isn't a problem, and the weight will actually help some tumbling and wind penetrating moves.

I couldn't find the wing area of your funky 40 on that sight, but from the pics I think it will probably fly like a hangar 9 twist at that weight. Not the best 3D plane around, but still acceptable by most standards.