hi, i do not have twins, but i put my 3 kids in my double stroller all the time, still, since they were newborn, 2 and 4. they are now 3 5 and 7 and they still all sit in together. its really expensive, it was a gift to me too, thank goodness. i have the valco twin. check it out on their website. its a side by side. it is huge, but handles beautifully, you can steer with one hand. the kids can lie flat, i change them in it, they can even lie on their belly. it folds up super easy once you get the hang of it. its wide but it fits through a standard doorway. its bulky and heavy when its folded. i flip it up into the rear of my minivan so i dont really ever have to lift it, i just lean it on the back bumper and flip it in and out, its great. if i had to lift it, it wouldnt be so great. i dont know if your carseats click in, a lot of them do. they sell adaptors for them. check the website for your carseats. they also sell a jumpseat that your 4 year old can sit in while the babies are in. i never bought it, i just put 2 kids in one seat, there is plenty of room with the seat reclined to double up. it is super sturdy, i used to sit on the foot of it to nurse or rest or whatever. it goes over dirt, grass, gravel, anything, even sand sometimes. i love it so much, its my freedom, we go everywhere with it, but its not for everyone. best of luck to you.