The RSST is the easiest set up there is. However, and this is important; once you have set up an RSST, don't assume that you now know how to set up all genesis type RBAs. When you go from an RSST to an AGA-T2, which is another very good entry level geny, you will have to contend with issues that weren't present before; like the fact that the wick hole in the AGA-T2 isn't insulated; nor is the tank bottom. The center post will require a delicate touch, with the tiny nuts, as opposed to the spring capture system on the RSST.
So, it depends on where you want to start. If you want to get vaping in the shortest amount of time; go with the RSST. If you want to really learn how to set up genesis RBAs, and deal with a steeper learning curve; go with the AGA-T2.