twins are good for top end power increase which is good for the track

i would run the GX style SU's myself especially if its driven on the road, and i do on my rally car

the weber/dellorto combo is great for top end power but robs the rest of the rev range badly, and they require frequent tuning and maintenance to keep them in good order

most people will disagree, but i ask them to come watch a rally with me one day and it's very easy to point out the downside there