The first image is of an Aerlit Shuttle's bobbin filled as full as it can get. The second image is that same exact thread on a Kumihimo 1 7/8" bobbin. If you do want to travel with tatting and like me still work with larger (size 10 crochet cotton) threads, you might not want to take full balls of thread with you. Working from shuttle bobbins, post shuttles, or even kumihimo bobbins is much easier to travel with and to work with.
I have seen some people say they hate bobbin shuttles because they don't hold as much post shuttles.
That may be true, but after winding the thread from a bobbing shuttle onto the post shuttle, I don't think there's enough of a difference for me to care about. I thought I had taken a picture of that, apparently I didn't. The difference between the Aerlit shuttle bobbin and the Clover shuttle was that once the Aerlit bobbin shuttle thread was fully on the Clover post shuttle I could have maybe filled the bobbin about 1/5th of the way and added that to the post shuttle. Working with size 10 thread that's not enough of a difference to care about. With very fine threads it might be. With the bobbins you can wind many at once and be ready to go when you run out instead of stopping to wind the bobbin every time you run out of thread, so there's that.
What I do care about is how convenient the shuttles generally found in stores are to travel with. I think this is why I keep trying to master shuttle tatting. Needles are long. That's another concern I have about if we ever have to travel. The needles are so long I don't think they'd get through security even though they're dull. Shuttle tatting means you can take everything with you without concern of losing them. But for me, even while needle tatting at home, I find working from a bobbin/shuttle easier than working off of a regular ball of thread. Part of that could be because I have a cat. If I have a bobbin or shuttle in my hands, she's a lot less interested than if I have a ball of thread on my chair with a nice long thread moving between me and it. I think the other part is that I sometimes have a tremor in one hand and I find needle easier to manipulate. I'm definitely not a graceful shuttle tatter.
The needles are long enough to require something around the length of a pencil case to store those (I still have mine in the plastic tube they came in but it cracked around the lid so I'm going to need a new storage for the needles soon). Shuttles though, don't present quite the challenge for transporting them. Several Christmases ago my mom sent me an adorable Winnie the Pooh keychain tin box just like this one. I've been storing smaller tapestry needles in it, but when I broke out the shuttles I noticed something.
I could fit one Aerlit shuttle with 4 bobbins and still close it. Or I could fit three of the Clover post shuttles (only have two to test with but since I could squeeze in the Aerlit one sideways too, a third Clover will definitely fit). Needless to say I ordered another of these Disney keychain tins. I did test a small sliding mint tin I have and it worked for the bobbins or the Clover shuttles, but the Aerlit hook made it just a little too long to fit in tins like that. So if you want to carry shuttles this way I'd definitely look for the longer keychain (I've only seen them with Disney characters and Coke branding, but I am sure if you had more patience to do a proper search you could probably find others).
I do wish the shuttle took regular sewing bobbins. The Aerlit bobbins are not as tall. I have seen a wooden shuttle on etsy that takes regular sewing bobbins but it also seems much larger than the Aerlit shuttle. Honestly, if you're as graceless as I am, you could probably shuttle tat using just a sewing bobbin and get a bobbin clamp to keep the length of working thread manageable.