Relle - I had the complete opposite.
1st birth - induced, and THE worst experience of my life,except I now have my beautiful daughter.
2nd birth - spontaneous, and same as you
I had a 4 and a half hour labour, found the contractions manageable with just gas, 16 mins of pushing, ... but up and showered within 30 mins of giving birth, quicker recovery, bonded alot better with baby.
So it might be more to do with it being the 2nd birth and you and your body knowing what to do!

I would totally recommend against an induction unless advised by your obstritician. Just my opinion, but I feel it passionately. However, if you are going to be stressed and not in a good mental state if you don't have the induction then maybe you should?