Having experienced two spontaneous and one augmented, I would prefer to have my 12 and 8 hour labours (for #1 and #2) than the 4.5hrs of tourture I had with a syncto induced third labour. I felt more in control of my body with the first two and despite being longer births, I felt I could work with my body more. During my third birth, I had my body producing it's own contractions, plus the syncto inducing them, so it was absolute torture for me.

I think that you will be pleasantly surprised this time round and having had experience with your previous two, you will know even more this time around and be better equiped to handle them. Even though an un augmented birth can take longer sometimes, your body is doing it at it's own pace which is better for you and the baby. Plus the level of monitoring will be less and you will be able to have the freedom to move around and this in itself can help a great deal in speeding up the arrival.

HTH.