All right gentlemen: shit has been whipped out, and test results are in.
In the first stage of both games, I can cling to the side of those red and white signs that have what looks like the "Coca Cola" logo on them and jump repeatedly to land on the top of them.
However, if you go to the end of the first section of 2-1, there's a pillar right before you ascend a ladder to the next area (to the left of Ryu here. In the PC Engine version, I could repeatedly wall jump on the right side of this pillar and ultimately land on top of it, but in the Famicom version, I just shoot up in the air, then fall back down and cling to the wall at the top. It's like there's an invisible wall that keeps you from jumping at the top of the pillar and landing on top of it. The tiny platform to the right of Ryu in that video exhibits the same behavior, though strangely in the PC Engine version, you can't cling to the side of it.
It's odd that in the Famicom version this sometimes works, like for the Coca Cola signs, but other times it doesn't. Anyway, my apologies to lukester for getting it wrong!
As for my opinion on these two games, what immediately disappointed me about the PC Engine version are the choppy parallax, the smaller sprites (making the game feel more zoomed out), and the soundtrack. But they're minor complaints, and the updated graphics might make up for it. I mean, just look at the bar scene in stage 1-2 of the Famicom version: hot pink floor tiles and wallpaper?