M.S.
Hi K., I think it's wonderful you've been able to stay home with your boys. I work full time (my husband too) and our 18 month old son and 4 month old daughter are in daycare. We both have to work to make ends meet. But we also agree that having our kids in daycare is in their best interest - they are being socialized, in a formal learning setting, getting experienced trusting other grown-ups and dealing with a variety of experiences, etc. (I'm sure you've heard all this). It's really hard because we don't get to spend a lot of time with them during the week, but we make the best of our mornings and weekends. Our house is a royal disaster though.
I think for the age your kids are, another important factor is that when both parents work full time, you are setting an example for your kids. They are seeing you as having an outlet that gives you a break from them and also makes you happy in a way. They get to see you as someone who enjoys setting goals and succeeding outside the home. And, they have the opportunity to be cared for by others and learn to trust other grown-ups to be there for them (to comfort and soothe and play with them too).
Good luck making your decision!!