I find the vert to have alot of body roll compared to my 325is. interested to see your take on having that much power.
I'm using h&r sports with bilsteins, e46 m3 rear shock mounts, eurethane engine and tranny mounts. The engine / tranny effectively act as a cross brace with the eurethane bushings. The upper strut cross brace further stiffens it. Next mod is eurethane subframe bushings. There's very little roll and not too much flex. I find it pretty nimble... but I'm sure a similarly equipped hardtop would be "nimbler" :-)