It depends on what you need. If you want it just for contests, then the small bag would probably be perfect: carry your competition set(anything but 4A) in it, plus maybe a practice throw or two and you’re gold. I rarely see anyone carry more than 6 to the stage with them. That’s where I get my numbers from. Holes in the foam for CWs or lube. Extra pocket to hold bearings, off-strings, strings, accessories.
I have seen the 24, which is a larger version of the 24. Yeah, it looks folded. That goes away. Maybe YYE should just let one sit out a bit and snap a newer photo. It’s made of a different material than the medium bag. It’s just as durable.
The small is very compact, easy to carry, almost like a book, and full, weights about the same. It has a shoulder strap as well, for even easier carrying. It can easily fit in a backpack and many glove compartments… The side pouch on the front is generous and can even hold an off-string if you want, as well as strings. The 12-holder also has a pocket in the front for holding all your extra goodies.
It’s ultimately up to you what to get. I have a small bag, which I like, but I fill it with beginner/newbie throws and I can take it with me to where I may be meeting with inexperienced throwers so they have something to try out. It also in my point of view gives the new kids a better impression of what I do because I have a case for it. For you, that’s irrelevant though.
If I was JUST COMPETING(note: I do not compete at all nor do I want to), I’d be very focused on what I am doing. The 8 would be more ideal for me. If I was signed/sponsored, it would be my 6 yoyo competition set, a practice throw(extra) and one for others to try.
However, if you need to carry 4 more… all I’m saying is the option is there. They even have a large one that holds 24 and it’s nice too.