I was there recently and it wasn't originally in our plans, but we decided on a whim to go. I'd say for $25 it's worth it. Maybe if you rush to the skywalk portion and just stand on the glass, sure it might not be great, but we took our time, using that audio tour thingy along the way. The sights are quite nice along the way, and I learned a fair amount while going through it.
We only stood on the glass portion for a few minutes as it was pretty busy, but it was more impressive to see from the back than on it itself anyways. I thought originally it didn't look too high but when you're looking over the edge it does seem pretty far to the bottom.
TL;DR version: Don't rush it and you'll get more out of it. Here's a couple pictures I took on my phone.
