Hello everyone! (this may be a second post, 1st one was an era)
I just purchased my Risers and they are SUPER! Amazing work out for
your abs shoulders legs, Awsome! So much fun, with every Bounce I
recollect my mother yelling "stop Jumping on the bed!" and I am free!
ha, ok too much info but yes these things are great fun!

My experience: Fedex drops off the huge box, Yes! Says Poweriser Im
Hyped! Take them out, stiff sturdy solid, then the rattling of the
cheesy straps ive heard so much about. (ive researched for hours on
end before buying risers/skips) Knee brace padding? You can find more
padding on a roll of toilet paper. Anyway thats besides the point, I
strap them on and Honky honky honky honky!!! It was true, then I was
attacked by three geese. 7090's stood next to a pole bounced myself
till I was able to let go and do it on my own. Excellent!

Modifications
First find some snowboard bindings, drakes are what I use also as
someone mentioned. 100 bucks. The stock bindings wont last. Also have
some loctite ready for your bolts. (this keeps the nuts from
loosening up on you.
Knee pad: leave the pad, wrap it with Rubber garage door bottom by MD
(home depot)trust, this is awsome! You wont need knee pads at all
after this. Then wrap again with black duct tape, looks good feels
great. Do not use heavy huge plastic knee pads, remember the pads sit
under your knee, you want a small soft natural knee pad that doesnt
cause buckling of your knee. maybe two. Instead of slipping them on
and cutting off your circulation, try wrapping the pad/s within a
neoprene knee brace on THE OUTSIDE of your leg. Play with the idea
you'll get it.
Honking: I tried oil, didnt work. So I disassembled everything,
replaced the major threaded bolts with sleeve bolts (makes perfect
sense) added heavy duty grease to every moving part. Smooth! Once you
take apart the risers you'll notice the dryness. (Note: The spring
doesnt fling open, once you take bolts out it stays in the same shape)
Thats all, if you have any further inquiries feel free to ask...I may
be over looking some things.

Oh Powerskips, are heavier than risers and the bottoms are different
material...louder when bouncing. Stronger though with a bow that lets
you get higher than what risers have available.
Ive used both
Have fun!