I was a Correspondent and Wholesale. They usually have the newest program that comes out. Their pricing is competitive but not the best and especially over the last 4 months. Their underwriting is top notch. You can call, email (firstname.lastname@flagstar.com), and you can do live chat on the computer which I find to be the fastest when trying to get a quick answer.
The technology is another top notch. Paperless uploading of loan files. Paperless closings through Doc Velocity.
Another thing many people do not know about them is they let you use their license to close out of state loans. You have a little more flexibility as a Correspondent but you can still do it under wholesale. They may restrict you to a certain # of loans in one state or not allow you to charge any up front fees. I do not know of anyone else who let's you do this.
They were running 30 days on <80% LTV Refinances in the 1st quarter of 2009. Large rate decreases cause them to have horrible underwritting delays and they were not giving free extensions on files like other lenders were. (Case by Case)
One thing you may not like is their recent credit overlays though. They are more narrow than they have been in the past. I fear Flagstar may be the next TBW! They did many of the same programs.