I'm sure you're right. 1/2 week at each makes sense to "make up" for the lost spring break.
My ex and I did agree long ago (we split up in 9/01 when DD was just a few weeks shy of 2) that things would never be exactly equal or fair, even if we tried. A good example is sleep overs. Ex and I basically split each weekend roughly Friday after school through Sunday after church and then Sunday afternoon through Monday morning. So, one of us has 2 nights and one of us has 1 night a weekend. We roughly alternate every other weekend. Now that DD is 10 she goes on quite a few sleepovers. Without exception they come out of "my" nights. Why? Because she goes to school in my district and I know the families more than the Ex. Also, it seems to be more of a mom thing to deal with the scheduling etc. In all these years no one has called the ex to set up a play date or anything, so it comes from my time. Do I love that? No, I don't. I feel like I miss more time than I want to with DD. But, in order to continue as much normalcy and regularity in DD's life as possible this is how it goes. In fact, she is going to sleep over this Saturday and we have plans with another family on Friday night (she'll be with us, hanging with their kids). So, although I "have" her two nights this weekend I actually won't spend much time actually with her at all. It makes me a little sad that it'll be 2 weeks til we get a shot at a weekend night to really hang again (since next weeekend I'll have Sunday night it's a different feel because it's a school night). Ah well, it's life. Sorry to be long winded and somewhat off topic. I guess my point is just that these things come up and you do what you can.