Suzuki 2 Strokes

I've been looking at GT750s for years, with the idea of building a mild custom with some minor performance improvements. It seems most of the bikes I see have later CV type carbs instead of early slide type carbs, whether original or aftermarket.
Or is this because most of the customized bikes are later bikes with original carbs, and all the early bikes have been restored and not customized?

So, is there any performance improvements with the CV carbs over the early slide types? I have a '75 model, and a good set of both type carbs.
Also, is bigger better on the later bikes? Maybe some 34mm slide types? The bike will eventually have Jemco pipes and pod filters, and maybe a shaved cylinder head.
I'm looking forward to some opinions on this, and maybe some experienced answers.
thanks
Mark

Porting changed through the years and carbs went upwards too to cater for the difference in performance at different rev ranges.
The early (non linked) carbs were harder to keep synchronised than the later ones, and the later ones sorted many problems that the early bikes had with 'hunting' on part throttle and hesitating when the throttle was snapped open to name two issues.
I'm sure folks who have GT750 will comment on these points.
Not sure about the 750, but the 380/550 tanks changed slightly as the fuel tap was in a different place on the early/late models to suit the carb position.
The taps were also different depending what carbs you had - three outlets or one, with the single outlet being much larger to flow fuel to 3 carbs.