Everyone have different driving style, results, taste for daily driving/drifting/dragging/etc. Each of Nissan's motor has its weak and strong points.
As for me, I like torque, yet something that wont drain my fuel money, reliable, inexpensive, and easy to find parts.
My S14 has the KADE, and I'm unsure if i should go SR or KADET. Im so used to my KA, which its power is found at the lower RPM end, I think the KADET will suite my style more than a SR. And mostly everyone does a SR swap, than KADET. KAT are just something different.
The reliability factor is unknown. There are motors out there that are beat on since it came off the factory line, some are well taken care of, and MAY last for good time.
I expect the KADET to drink gas like its nothing.
If the KA blows up, theres plenty of KA to go around. For parts, just head down to the local auto parts store. I know the same could be said about the SR, but there might be a few parts that a local auto parts store doesnt supply, but its almost guaranteed that they have KA parts.
And i heard the CA is just like a mini version of the RB.