well I really can't claim to be an expert and I am yet to get "the twins" as I call em properly tuned on my coupe but I find them fine for street driving it's really only the excessivly large cam I installed in the motor that makes the whole setup a little tiresome to drive arround at sane speeds.once shes above 4000 rpm tho, the quick trip to 7000rpm and the induction noise from "the twins" makes that climb to 4k on the tacho a long forgotten memory.

Since putting them on we've only given her a rough tune but she seams to run fine, i've done a bit of twin SU tuning and once you have the basics you'll be wondering what the fuss was about. as people have mentioned it's the base tune thats the hardest, as you need a good selection of bits, jets emulsion tubes ect.. to get it right the first time.

I considered twins again for the next build but am opting for single sidedraft as the fuel does seem to disapear with twin webbers (mainly cause it's so much fun driving it at full noise) I tend to think that the single properly tuned will on the street give just as much fun and less of a shock at the bowser.

good luck