Stripe is a established company that has a polished interface and support. Balanced is a fly-by-night.
I have one site with Balanced and one with Stripe Connect, and this is the defining difference.
- Balanced changed their API and completely broke all transactions.
They didn't even send out an email. Never happened with Stripe.
- Balanced once "held up our site for review". Our marketplace went down with no notice or email. (And no explanation when I emailed them, just a response it was being held).
- balanced.js can take 10-15 seconds to load, causing the page to hang (we implemented lazy loading just for balanced, but the page is not always ready when needed).
- IRC support: Balanced has ~40 inactive users and ~10 users online ATM [in the middle of the U.S. night there are no user, and the inactive users have no AI personality]. Stripe has at least 100 active users, and I seem to be able to get an answer whenever I need to.
- etc.
Balanced has one killer feature - your users can sign up and start selling immediately, they don't need to validate themselves to sell, only to receive money.
They are more likely to follow through if it's easy to get into the system. But the risks are real, and should not be ignored.
Also, if it matters, the fact that Stripe can accept payments in multiple currencies can be a killer feature as well.