I have no regrets, but it is hard work. I'm up at 5am every morning to walk / run mine before I head to work, and weekends am lucky if I make it to 6.30. He's an enormous dog (over 8 stone) who thinks he's a lap dog, and is the most gentle, loving creature, but does scare other dog owners who don't know him. We got him as a puppy from a rescue, and he's a mix of a few breeds so have been lucky he's turned out to have such a fantastic nature. His size means all the walking falls to me, as DP didn't want one, and he's far too big and strong for the kids to walk.
We also live in Australia, so winter is pretty short, and not too cold - though have had plenty of walks in the rain. I am a runner though, so have been enjoying the fact that I'm out and about twice a day, and now we're back into spring walks on the beach and in the bush are a real pleasure.
We both work full time, DP is at home twice a week, the other 3 days we pay a pet sitter to come in for a couple of hours each day, and my kids are older so get themselves home by 3 each day.
Our house absolutely smells of dog, no getting round it, and the garden is wrecked but for me it's worth it. I wouldn't have been saying the same when kids were little though, think the stress and workload would have been too much.