Right - first things first or the price they are absoloutly fantastic.
Compared to Powerskips i believe their on par the height is great, they sound great, they perform well and are substantially cheaper the only slight issue i found was a bolt came off which was attaching the spring to the rubber and immediatly the rubber had moved position, luckily i heard it hit the floor and stopped bouncing.
I do understand this could happen with any stilts and just stating what happened when i was on them.
Compared to SJ's - The height was similar they are slightly heavier which has been mentioned in previous posts so i believe you would be paying the extra cash for the durability and the frame for the SJ's so it would be all down to personal preference and money situation.
By far the best Pro-jump stilts i have used and these really compete against the other more expensive makes. I will use them a few more times before making a decision on which order i believe the stilts currently sit in ( best to worst )
To round it up really good stilts at a great price
Paul.