Have a couple different buckets - one is the stock Kubota bucket with the trapezoidal/truncated-triangle shape with the height being about equal to the floor depth, and the top edge placed at almost 50% of the floor depth. The other one I have is a W.R. Long 1.885 profile (rounded back, height very slightly shorter than the floor depth, with top edge set further back relative to the cutting edge).
Have also used the longer floor skidsteer buckets (on a skid steer), so have a few different perspectives/opinions when it comes to bucket shapes.
The long floor buckets do provide a bit better visibility of the leading cutting edge (more so on the skid steers, though they don't work miracles on a tractor where the engine is always blocking visibility). Personally I prefer the long floor design or just even having the top lip further behind the cutting edge when digging/scraping as it doesn't roll the material as far forward (or out of the bucket).
On the other hand when it comes to scooping loose material from a pile having that top edge a bit further forward can make for a better cup when lift up through the pile since it's less likely the top lip will end up below the front cutting edge on the lift through the pile. The design also tends to keep the cutting edge closer to the loader pins which can reduce the amount of force required from the curl cylinders. In turn that can make a noticeable difference when curling for the uplift (through a pile) ...especially when pushing into the base of a pile of heavy material.
Does it make a huge difference? Probably not on a per-bucket basis, but over the course of dozens (or more) of scoops the differences can add up.....though even then it may not be enough to justify having multiple buckets for everyone.

..... in some ways it's almost like the difference in shape between a dust pan and measuring cup (or ice cream pail).... either could have a larger volume, but each may have it's own advantages for scooping material depending on how the material is piled/spread......
Just my $0.02 though ...and I'm far from an expert when it comes to operating hours (just have a fairly wide set of different experiences).