I have a rave slider that gets used a fair amount. Here are my thoughts:
Floating sliders move. Period. That doesn't make them "bad".
The advantage of a floating slider is that it works with changing water levels and you can take it with you. I carry mine on the top of the houseboat and it takes me about 20 minutes to rig it and get it set up. Not a big deal at all.
An advantage of an inflatable slider is that the sides are fairly soft. Just about everyone who has attempted the slider has crashed into the side at one time or another. It is much nicer to bounce of a tube of air than a 4x4!
If you would like to see my Rave Slider in action click here:
http://pages.sbcglobal.net/rmcinnis/wake_pics.htm Note that I am 48 years old, 190 lbs, and not very good at wakeboarding. Ignore the lack of grace and style, look at how the slider moves (or doesn't). One of these days I will get a video of my son doing his tricks on the website, much more interesting!
What prompted me to buy a Rave slider was the day my son and I went out to Orwood (California Delta) to check out the sliders there. We watched guys fall and smack themselves pretty hard into the posts and rails. Then I watched as a support beam BROKE as the rider was going up the ramp and he got then end of the rail in his gut. He wasn't hurt bad, but it sure looked bad! I decided right then that I would rather invest in an inflatable slider than pay the hospital bills!
I bought mine off Ebay for about half what the retail rate was. I have had it for about two years and it is holding up well.
Rod