It will be stiffer with the tubular wishbones because of the rose joints replacing the poly bushes I would have fitted to the tt wishbones. I currently have poly bushes all around and would like that bit more. The tubular wishbones also allow far greater adjustments to the suspension geometry and are a bit lighter.
In all honesty I ain't very concerned with ride quality as its not great as it is, I'm just worried about the durability. Surely someone has used these on the road before?