I'd taken some pictures about 20 minutes ago. They're not of the greatest quality, but they show the differences in the valves.
Intake: the SC is on the left; the split port is on the right. The split port is bigger. The split port is polished, so it is a little more worked than the SC in this case, but the angle of the backside of the valve is just slightly more angled, and note the size of the stems. Those watching their valvetrain weight take note!
Here's the exhaust valves--again, the SC is on the left, the split port is on the right. They're the same size (looks like the split port is bigger, but they're not aligned properly.....had to hold 'em with one hand and then take the picture with the other). The angle of the backside on the split port pretty much mirrors the valve seat face, if you remove some of the valve seat face margin (which I did......in stock condition, the margin would impede low lift valve flow more by hindering the flow along the backside of the valve). The stem sizes aren't as evident because of the picture, but they're the same sizes as the intakes in both cases. The weight difference, as i've said, is noticeable......the exhaust valve is way lighter on the split port. Again, that's up to oneself as to how much value valvetrain weight savings amount to, but it all adds up in a build. In this case, as well, the split port received a polished finish, but the SC valve is as modified as you could get it, because the valve seat margin can't be ground down for the most part, based on the contact patch with the seats. I still have to lap the valve properly, too, as the initial lapping was just to see where the valve seat contacts....there's a lot of pitting.
Edit: also, in terms of flow, the single ports look like they have the advantage, but velocity is likely down from the split port. One thing that I noticed with the split ports is that if you gasket match them (which I did), the high end/ high rpm runner in the split port forms a perfect horn-like shape (wider at the port entry, tapering down towards the bowl) to help pull air into the cylinder. The single port has a nice square shape, but the high rpm runner in the split port is a perfect round circle, which is probably going to equalize the airflow along the wall sides, port roof, and port floor. The SC's don't flow that well on the sides of the port (based on some flow testing that I did). Also consider this: the turbulent runner is the low rpm runner in the split ports, which means that the port roof in the SC which gets corrupted by the injector area is
not in the air path. You're getting as close to a perfect tube into the intake bowl/ cylinder as possible. It also means that you can mirror finish the bejeezus out of the high rpm runner, since there is no fuel going through it until the bowl area and don't have to worry about atomization problems until the bowl.