Comparing the 91028 with the older 90143 Lifetime Monkey Bar Playset.

The newer playset is a redesign of the older monkey bar playset model 90143 (and if you're looking at the primary colored model it's 90177).  Why the change?  Lifetime took a look at the customer experience from beginning to end.  They realized that the newer design could be packaged in a much better way, preventing damage in shipping and making it easier for drivers to load and unload onto trucks.  What's more is that the customer gets a better delivery experience.  The carrier calls for delivery, rolls it onto the lift gate (little elevator on the back of the truck), and rolls it onto the customer's property using the pallet jack.  

What was redesigned?  Nothing major.  The slide is a 2-piece slide on the newer model which makes packaging and unpackaging of the slide better without compromising the slide integrity.  

Another change is that the newer design has a more durable rubber chain coating with a 140lb capacity per belt swing.  That's a conservative estimate, but that is the official published weight rating.  Without losing any of the features such as a fireman's pole, trapeze bar, monkey bars, etc - the footprint is a bit more attractive as it's condensed by about 1 foot width-wise.

Bottomline - Lifetime wanted a better customer experience without compromising quality, integrity, and product features.  They are experts in playground manufacturing and have become the number 1 playset manufacturer in the USA.