I have an ECO I have carried for 5 years in my work bag, and it works just fine. It has never cracked or leaked. I have also never tried to disassemble it, just cleaned it by rinsing. several people have noted that the threads in the barrel have to be carefully realigned when you are piecing it all back together.

I also have the VAC700R and the Vac Mini, and have flown with them. I haven’t had any cracking issues, though I have owned both for less than a year. Again, I don’t take my pens apart, though they do get banged around in my bag all the time.

I have read about these cracking issues, too, so I don’t know if I’m just lucky, or if there is a bias because so many people have TWSBI pens so the failure rate might be low, yet still have more issues crop up than less popular pens.

Also, all of my pens state they are made in Taiwan, which I have heard means they tend to be of higher quality. But that’s just something I read on a forum.

I love the ink capacity, and I don’t usually unscrew to top unless I am writing for a long time. There’s usually enough ink stored in the job to write what I need; I will release it periodically, and that seems to be enough.

Hope this helps!