L.,
I cannot say enough good things about the Phil&Ted stroller. See link below. They used to have a nice photo spread of the different ways to use it, but I don't see it now. When the second child is an infant, the 'main' seat fold down (Easy clips & Zipper) and lays flat. The 'back seat' switches up top (Super Easy to move - 2 buttons to push while you pull it out/put it in) and the toddler will sit up a little higher. My son loved it. When the baby is ready to sit in a traditional stroller, strapped in, the back seat goes into the position that's in the photo. Believe it or not, my kids fought over who got to sit in the back seat. You will also NEVER find an easier stroller to push. My second child was a big boy and I could have both in or carry one of the kids and move around with one hand in tight spots - easiest stroller in the world. Front wheel pivots like a jogging stroller, but it is not designed to be a jogging stroller.
-if there was anything I would change about the stroller -
When my youngest got a little older, there didn't seem to be a graceful way of getting him into the stroller (you want the heavier child in front before you put in the second) It just took a little bit of time.
It's not overly heavy, but it isn't a one hand break down. I think you have different weight expectations when it's a double stroller. When it folds up, it's not exactly compact either.
For air travel, you'll have to pull out the second seat to put it under the plane at the gate.
I love my diaper bags and always hung the diaper bag on the strap. The stroller isn't really set up so you can do this, although I still did at times.
Even with the things I didn't care for about this stroller I would buy it again and again and again.
With that said - it actually breaks my heart, but I have to sell mine. My kids are too big for it now. I'll be putting it on Craig's list in the next couple of weeks if you would like to meet and take a look at it. (I live in N Raleigh off 540) We also have 2 saddle bags that attach to the side or handle.
Hope this helps.
RC
http://www.philandteds.com/nz/classic_08_1.htm