I have been going back and forth on whether or not to go with a double this time, or to just get another travel system.
DD1 will be 2.5yo when DD2 is born. She is pretty independent and we don't use a stroller a lot anymore, so it makes me think we probably don't need a double, but I wonder if there are times when I will really regret that.
Does anyone have any experience with that kind of age range and whether a double was helpful or just a waste of money? Thanks!

Re: S/O Double Strollers
We had two under two last time and will again this time. So my first was 18 months when baby was born, we still use the double now and he will be three in September. But he likes to sit and ride. We got s boogie board for our city mini double for him to ride once baby gets bigger and uses the other seat. I plan to baby wear a lot in the beginning, it's nice to strap the older one down in certain situations. Maybe something like a sit and stand would work for you or get a single and bring a carrier if you are somewhere where older LO may get tired of walking.
I'm glad to see this post and am going to watch for the answers to your question!
We'll have a 3 y.o. when the baby is born. Our toddler is very independent and likes to walk, but I think we'll probably get a double stroller for times when he gets tired (e.g. the end of a long day at the zoo) or too rambunctious (e.g. while I'm shopping). Of our two strollers (a BOB and a Graco Metrolite), I like the BOB the best. But I don't want a side-by-side stroller, which seems to be the only option with the BOB Duallie,so I'm hoping for suggestions for a front-to-back double.
Look at the contour optima tandem stroller I thought it was really nice and versatile