In my experience, Fidelity appears to offer some of the best deals out there. And as others have stated, also some of the slowest response times from their agents. I avoid them as a buyer and seller.
As a buyer, I want someone to be as locked in as I am when I am in the purchasing mode. As a seller, I want to know that when the agent gets an offer they contact me IMMEDIATELY. I don't want missed opportunities. I'm actually paying for just that. Not working on weekends? That won't cut it.
One HUGE advantage, IME, with DVCRM is that my agent responds within the hour 100% of the time. I can send a question about anything and I've never had a response time of more than an hour. Not once and I ask a LOT of questions

You will likely never get the best deal with them though. Gotta weigh what's most important to you.