We do not offer follow-up services as we believe that sending claims out accurately reduces the follow-up rate to approx 5%, while increasing the cash flow to practices.
I've been solo 4 years, and we've always done in-house billing. I like the fact that my biller is right under my roof and I can talk to her anytime I want, face-to-face.
I would caution anyone against using a service that doesn't have followup on claims.