This, to many, is the key flaw of the Skyliner. Yes, the "passive filters" can offer some breeze at that height, but to be inside an enclosed space on a hot Florida afternoon is not fun. Thankfully, the rides can be short, but it's still amazing Disney never popped for a better cooling system, as a Skyliner ride can sometimes be uncomfortably warm for guests.
As a new ride system, the Skyliner is prone to some problems. There was a case of a couple crashing, but Disney has apparently fixed that issue. Yet the Skyliner can still be affected by bad weather and sometimes needing to slow or stop at one of the stations for some problems. Thus, guests may be in for an unexpected halt which can be troublesome with the lack of AC.
Some blocked views
For the most part, the Skyliner gondolas offer some great views. However, guests who board those with characters placed on the windows may not get to see them. While the decorations look great from the outside, they mean those inside can't see the same views as the unobstructed windows. Because guests can't really pick which gondola comes next for them, it's a luck of the draw if the Skyliner offers a good view or not.
Fear of Heights
True, the monorail is a bit high up but still "grounded" to the track. But the Skyliner is maintained at least 20 feet over the ground and can go up as high as nearly a hundred feet at some spots. On very windy days, that can feel even higher and could cause some anxiety for riders. The Skyliner can be a wonderful ride but a nightmare for those with acrophobia who may not be able to take so high up for so long.
Which is better?
So which is better in the end? It might come down to personal preference as some guests will enjoy the Skyliner for faster loading, some great views and a smooth ride. However, the lack of AC is a blow against it and the fact is that some guests will enjoy the history of the monorail more as well as its great showcase for Disney parks. Thus, the monorail has the edge, but the Skyliner can still be a worthy ride for WDW guests.