Excellent solution for SMB. We switched from QuickBooks and loved it from the very first sight. Intuitive UI, good reports, 2-minutes integration with Stripe. Xero is a good example that even accounting software can be exciting :)
Very simple to issue invoices. Colleagues without a finance background quickly learned how to issue invoices. Integrates with Stripe so customers can pay directly from the invoice. Payments (and outstanding invoices) syncs directly with Xero as well so you know what's happening. Straightforward!
Our Customer Success team uses Xero to send invoices to our larger business customers. The invoicing settings for things like alternative payment location (check, etransfer, etc) aren't exactly what we want, but so far it meets our irregular needs.
Pros: Easy to use, lots of integrations, strong focus on being open and easy for developers to build on. Xero can scale with you up to 100's of employees.
Cons: Fairly spartan interface but it gets the job done.