Sell flip home self or Use realtor?

[Michelle S.]

The deal:

Realtor 1 charges 1% to sell my rehabbed home and she got me my 1st rehab home at a good price. We don't agree on everything at times, and she is older so she makes mistakes. 18 yrs exp.

Realtor 2 is offering to sell for 3% and has 10 yrs exp. She helped me get a code guy off my back that was overreacting about our rehab. She says she's a master negotiator.

Me - I'm a pretty smart, detail handling person. I figure I know the most about the home and think "no one knows a product better than the person who made it". I realize I have to handle the contracts, negotiations and showings. I have a good Title Co picked out. We went over budget on this one so I figured I could recoup some funds if I sell myself. 

What is your professional opinion? Who has sold themselves? Any issues? Would my original realtor be unprofessional and/or upset that I didn't use her?