I have both the ball cap and the directional cap, and to be honest, they sit in the closet with my other glass.
When I first got my Switch, I fell in love with it's simplicity; everything is integrated and the pieces designed to work together. I especially like how the basic dabbing cap slips into the bubbler attachment. The silicone gasket attached to the cap makes a nice clean seal.
I know, as an option, I can put the silicone seal directly onto the bubbler instead of the cap. But personally, I don't like doing that as it restricts the opening and you can no longer slip the dab cap into it. To me, that seems to defeat the original intent / design.
The directional cap is a seriously nice piece of glass. I've tried it a few times but I still prefer the standard cap. Without a silicone gasket, you don't get a perfect seal with the bubbler. If you do use the seal on the bubbler, the restricted opening prevents the cap from seating fully on the bubbler. I don't know, it just does't 'feel' right to me. So what I did instead was buy a silicone o-ring that slips snugly onto the cap, as shown below. This still provides a decent seal while allowing the cap to slip into the bubbler nicely. It works very well like this.
To be honest, I haven't even tried the bubble cap. I suppose it works as intended. But I go back to my original point. You don't get a good glass-to-glass seal and I just like the way the standard cap and bubbler work together (with the seal being on the cap).
Just posting my experience and preferences. The Switch is absolutely wonderful and is my favorite way to do concentrates.