Hi - I had 2 c-sections (11 & 12 years ago) and am very satisfied with my abs. Right now, I have just a little extra fat covering my mid-section, but in the recent past, have gotten very good definition after eating healthy (lean protein with every meal, lots of veggies and some fruit, small amount of complex carbs, drinking LOTS of water and getting the good oils), making sure I get enough cardio, and strength training 2-3 days weekly, working my abs anywhere from 4-6 times a week @ 5-15 minute sessions.
I found that primarily, cardio which burns the fat is my biggest ally. Then, the toning aspect comes in and I've found a mix of different exercises works. Planks, traditional abwork and Pilates/Yoga produced great results when I do them consistently. I love the plankwork contained with the CTX series.
I will say however, that there is a little bit of loose skin that won't go away, but it really is barely noticeable because I've found that with drinking tons of water and with the ab exercises, that skin does seem to tighten up. It's very do-able! I never thought I'd be happy with my mid-section, but I am. I'm actually quite happy with the results I've achieved using Cathe tapes, and I didn't think that would happen.
Lipo just removes the fat, I found that the loose skin is really the culprit, but like I said above, that loose skin really can be tightened up with hydration and exercise.