Folding kayaks will provide the ultimate in performance if you are interested in paying 3-5 times as much as for a kayak like the Advanced Elements frame kayaks.
The question becomes when and where will you be using the kayak.
The Advance Elements is fine for lake and slow moving rivers or back bays but not something to take out into the ocean. Windage is a factor and an inflatable will be blown around more but not enough to make a big difference. Where I kayak in the Pacific Ocean anything without a rudder is going to be a major pain to paddle as the prevailing winds are going to be across the beam of the boat.
The Sea Eagle type may be fine in a lake but not very good when there is current to contend with. Some inflatables will take a small trolling motor and this can make paddling easier and be useful for using the kayak for fishing.
With any take down water craft a factor to consider is where it will be stored for travel, how heavy the largest part of it will be, how easy is it to move around for one or two people (we found our Porta-Bote easier to manage than a deflated 11 ft inflatable in its bag), how you will secure it to keep it from "walking off" when left unattended.
There are decided advantages to having a small utility or boat trailer and there are very lightweight trailers made specifically for use with kayaks and canoes. A canoe trailer and two used canoes or kayaks can be bought for a lot less than the cost of a folding kayak and you well get a lot more use when it is easier and faster to get out on the water.