I think I have more experience than most who voted with both platforms (specifically- E30 convertibles and E46 sedans).
E30 verts are very fun. That said it would not hold up well to a stiff suspension. It's not a stiff chassis and I think it might ruin it. (I have a red E30 vert as well). Keep the E30 vert stock.
If it was a coupe or sedan it'd be different.