I use my personal ECV, and I feel like I have been beat up after a day at AK; even with a heavily padded seat, sometimes it feels like there just isn't enough shock absorption!
It's *so* pretty, though. And there is so much to love about AK. I can't stay away!
Worst thing I *ever* experienced on wheels was at Silver Dollar City in Branson, MO. They have a bridge there that is an old bridge. I remember it from when I was a little kiddo, back in the 70's. Over the years, a thick "wedge" of beautiful green grass has grown up between the planks that make up the bridge. The grass now stands about an inch tall, and is so thick that it doesn't really compress when you step on it. The planks themselves are probably 8 to 10 inches wide. As you approach, it looks, for all the world, like a beautiful old bridge, with soft mossy tufts between the planks.
So... I didn't realize how tall that grass was. I also didn't realize how firm it was, and what was about to happen... I rolled down the slope, and hit that bridge and experienced the singularly most painful thing I have ever done on my personal device. It felt like I was rolling over a giant washboard that wanted to kill me. I literally had to go to First Aid and get some Tylenol and rest for a bit after, and my physical therapist lectured me for *weeks* after that, because that's how long it took to recover.
Now when I go to AK, I remember that stinkin' bridge, and the pavement isn't quite so bad! LOL