I'm looking to buy some leads and want to make an informed decision. Have any of you used the following leads companies? What have your experiences been?

1) Meridian Leads, Florida (Owners, Bob Squires and Brian Frolich. I've been told that Bob runs Florida and and Brian runs NY... I'd be working with their Florida office) - meridianleads.com
2) m4-global (Owner, Wayne McKnight) - m4-global.com
3) Call Qalifier, a division of Extreme Traffic (Owner, Scott Eli) - http://www.callqualifier.com

Thank you.