You Funco guys crack me up. They are a great car, well built, really fun, great support. I had one and really liked it, but as the thread starter asked about, here's what I didn't care for.
First was the low sides. Not so much the appearance, although kinda ugly(note new ones look a lot better) I didn't like the exposure to the occupants. I felt safer with the standard higher side car. Particularly if you roll over, which I had the pleasure(or not) of doing. Hence the helmets and wrist restraints are a good idea for all, and especially with these. My opinion is easy to get into, easy to come out of.
Another is the air bags. Although easy to adjust for weight, passengers, etc, I think they are the limiting factor of the suspension. I think it's pretty much a given they just don't run the big bumps like those "other" cars you talk about, and don't ride as plush. But, this is the sacrifice to keep the car low and stable, and a good slider. But that's what they do. Lots of fun there.
The other thing is the Subi. I really liked mine, BUT I REALLY like the drivability of the V-8. Low torque is my game, regular old cheap gas, no race gas, no mixing of race gas. You miss a shift or what ever, just roll on the throttle. 4 people in the car cruising, no problem. The V-8 is on it's game and user friendly. I did the revving, going on boost, zipping around, and while fun, just not the same. Nothing like the rumble of the V-8s. And I think it's also a given that the Funco's are a better duner with the Subie.
So IF those are negatives, that was my issues about the cars, and I moved into the bigger, plush V-8 car and love it. All in all, it's been said many times, what do you like to do? No way a bigger V-8 car is gonna stay with one of your short wheel base, light, Funco's. I give you that. But on the flip side, I think there is duning we "big shiney", just sit at the hill, or the drags cars, can do that may not be to the Funco liking.

So there is give and take on both ends.
So now don't all you Funco owners get all riled up and start plotting your attack, I'm just saying. So as you drink your cool aid, thinking the bigger cars don't dune fast, or fast enough, I think there may be a couple of groups that may dis-agree with you.