I will agree that Truggies are heavy by nature,
But it seems that some MFG.'s have a better handle on where the weight is and is not on the chassis. I drove the D8T, and for what is looked at as a heavy truggy, it felt much lighter on the track to me. The Losi 2.0 truggy I think is one of the lightest if not the lightest turggy on the market and it shows. The drive train is very free, meaning has less rolling resistance than some other truggies. That has to be a help. Add in the optional light weoght parts and the rotational mass is reduced helping more.
I like the unsprung weight idea. Makes sence to look at on a truggy.
I have the RC8T CE and I will agree that some days it feels like a pig on the track. Other days it feels perfect. I suspect that may be a setup and driving issue, but it could stand to be on a diet in places. Wish they had more light weight option parts for the drive train though. Light weight spur gear would probably be a hot item. They do have the light weight out drives for the buggy that can be used on the truggy, so that would help some. I used the alum center axle cups and axle stubbs. It helped, but the truggy is hard on those parts and I broke two stubbs off.