I'm working with a busy, talented vendor who does great work. The biggest drawback is they struggle with communication.
A work request goes on their To-Do list, but they can't or won't estimate when it will be finished. The work is brilliant when it comes in, and deadlines are met, but the awkward silence during the development process can be disconcerting. You have to decide whether the level of work is worth the silence.
If you do awesome work and your dance card is full, you can let customer service slide. Most of us don't have that option.