We also have a Rainbow Swingset and I'll also attest to it's stability and it's VERY well constructed. We've had ours for 4 years now, and it still looks like new. It is VERY sturdy, I've had probably 20 kids on it at once and it didn't even flinch. They are very expensive, but are worth it. They are made of untreated redwood, so they are naturally bug resistant.