I don't think anyone can really know the answer to this one - once you have your kids you love them, so even if you might have chosen not to have them your commitment clouds the issue for you.
You mention guilt, Spacemonkey. One of the best mothers I know told me once that 'Motherhood and guilt go hand in hand'. How true.
I find I relate strongly to your feelings, Trifle. You say that you are complimented on your mothering skills; my DH swears that it is the guilt about feeling the way I do about motherhood that drives me to being a good mother.
After my first was born I had horrendous PND. Her father was a rotten abusive git and I was too emotionally demoralised to leave. He bullied me into having another and I spent the whole pregnancy terrified in case I had another depression (I didn't). He dumped us when DD2 was 14 months. I had to bring the two of them up along for the next five years until I met my DH.
DH is a wonderful man and has, for the first time in my life, given me everything I ever asked for, loads of attention, a dream wedding, an equal partnership, great fathering for my girls. Therefore I felt unable to refuse his strong desire for a child of his own, much as it was the opposite of what I wanted. How could I deny him that when he had given his life to me?
Where does what we want fit into life????
Now I farm my DS out to a childminder where he is much happier and so am I. My DD1 asked me, don't you love him then? Of course I love him. I love my husband but does that mean I have to enjoy washing his socks? 99% of childcare is just s**t-shovelling and no one wants to complain, cos people will think they don't love their kids.
As for all you mums who love every minute of it...bless your hearts and good luck to you. You make me feel ashamed - but that's my weakness, not yours!