In some recipes I use CAP and TFA interchangeably. Vaping them solo, the differences I've noticed are the TFA is stronger, "spicier" (some might call it peppery in the same way TFA VBIC is if used at too high a percentage), somewhat less eggy with a more forward vanilla, and it has light throat hit, where the CAP is more velvety smooth, but also lighter on flavor overall. I think people favor CAP simply because it's the kinder gentler VC, but I like TFA's somewhat bolder approach. I think you could get away with lower percentages of TFA. If you want to get it closer to that smoothness of CAP VC1, TFA VC combines really well with Flavor West Sweet Cream (I repeat, Flavor West Sweet Cream, not the CAP/TFA versions), but if you're a V2 type, you will not appreciate the Diketone madness of that combo.
TFA Vanilla Swirl is a good flavor. I use a surprisingly large amount of the stuff, but I don't find it similar to either Vanilla Custard or CAP VC2. I have yet to figure out CAP V2. I don't really notice any off flavors from it (the vomit people mention), but when I try to sub it for diketone VC, the results come out flat, one dimensional. I don't know if it's muting other flavors, or if it just lacks notes the diketone VCs have, but it doesn't bring me to a point of satisfaction.