Seller financing vs. hard money loan

[Lynette Fisher]

I have a seller willing to do seller financing. Owns property outright. Nothing official, but she suggested 10k down with paying the additional 50k over 5-7 years. From what I understand...

I will need to pay the 10k down and all rehab cost out of pocket(approx 17k in rehab). 

I have a HML that will do a 9% interest only 12 month w/100% rehab funds. 15% down. I can cash out refi after 6 month seasoning.

To me, the HML route leaves me with less out of pocket expenses. Everything I read says you don't pass up seller financing. I am still learning, please let me know if I'm misunderstanding this.