The point is that the Sun Mountain Micro Cart is a four wheeler, without the instability that allows the occasional topple over that happen with the three wheelers, just like four wheel ATVs are more stable than three wheel ATVs that were a terrible idea.
The Micro also folds simply, quickly, and smaller than Clickgear, etc. I'm gone long before my buddies get their Clickgears stored for travel.
How much experience do you have with the 3 wheelers? Just curious as I had heard this about them before, but had also heard the "handling" of a 4 wheel was not as good as the 3 wheel. I am a big fan of the way the Micro Cart folds up. Going against them besides the "handling" issue is that I have heard the small wheels could be an issue with them.
I have a pretty large trunk I suppose, I have an Impala, so its not a major issue, but wonder if the Sun Mountain with it staying on the bag or folding another cart up and putting that in their as well is a better space saver.
I don't know what you mean by handling. If you mean turning, they are the same. You have to get the front wheel(s) off the ground to turn no matter how many front wheels there are. I had the Sun Mountain three wheeler for several years before getting the Micro. When I went to a bigger bag, I couldn't get both cart and bag in Mazda 3 trunk, unless I got the Micro.
My friends have the ClicGear, and their folding unfolding is tedious compared to the Micro.