I guess I just ask myself if it would be any better if I was working a 9 to 5, and my own kids were in childcare. For me, I don't have the option of not doing anything at all, we need the extra income if we want our kids to play sports (or wear clothes, haha).
I think about it that way, and I realize that I would absolutely be burnt out if I was doing that. So if I am going to be dog-tired and have a messy home, I may as well spend the day with my own kids! Not to mention, then I would have to commute (in winter, ugh!) and find a place that I could trust to take my own children (not an easy task, for sure).
I know my older boys "suffered" a little at first, but it's really not that hard on them. It was just an adjustment. And my 3 yr old daughter has days where I know it's not the best thing for her, but there are also days that I am so grateful she is surrounded by kids to play and interact with. I also really make a point of taking a few minutes to sit down each day. It's a little easier to justify the more pregnant I get, too, hee hee. I think the thing that irritates me the most is the mess. I am not a natural housekeeper to begin with, and so it does seem to be compounding. A little bit worse each week! I am seriously considering having someone come in once a week to do floors, dusting and bathrooms. It might just be worth the money.... :P