Yodle screwed up my client's local SEO. I advised him against hiring a second SEO unless our efforts would be complementary. The rep told him it would not be an issue. He is now screwed on local and in 11 more months of contract. My efforts have been effectively coopted because I had JUST begun his SEO and within a week they established citations on the highest PR sites with the wrong phone number.
My only option for this client is to create a DBA with a different business name for yodel and then brand his main business (my project) differently with different address and contact information.
If you're not hiring a REAL seo company, go ahead and use Yodel (unless you already have rankings, because they will DESTROY your existing rankings with duplicate info).
If you have no website, no rankings, no knowledge and don't care to ever own the assets you pay to produce, use Yodel.