I started c25k programme at about 230, it was great and I loved it. Not sure about how much it helped me to lose as I was doing other exercise at the time.
I did put it on hold though because even though I wasn't experiencing any pain I still worried that being overweight was going to put undue stress on my knees and may cause me problems in the future (Mild knee problems in the past) I am looking forward to running again when I hit a normal bmi though.
About stalls ,yes, running did cause my weight loss to be less linear. I felt like I was holding onto extra water especially in my legs, and I know it's not very easy for women to gain muscle mass but I swear I just felt like my legs were getting even bigger. Also running more than any other exercise would raise my hunger a lot. This was also a small part of the reason I put running on the back burner.
Love c2k as a running programme though, It has made running accessible to me. I used to think people were either born fit enough to run/jog or not, progressing though the programme gave me happiness almost equal to standing on the scale and seeing it go down