I have Bugaboo's, I had a Chameleon with my first. When my second came along I got a Britax B-Ready tandem so the car seat can go on bottom, but after my second got older I got the Bugaboo Buffalo with the skateboard that attaches to the back so my son can ride on that and my daughter on the seat. Now baby number 3 is on the way so we just got the Bugaboo Donkey so baby can be in car seat next to my daughter in the seat and then put the skateboard in the back so all 3 can ride. My son (4 years old) is still very distracted while walking so it is already hard enough getting him to keep up walking next to me without him getting distracted and stopping every time he wants to look at something, then we have tried having our daughter (2 years old) walk and she runs and also is distracted a lot by things she wants to look at. So that is why I am opting to get a strollers that accommodate our needs.
I believe it is a personal choice to get a new push chair or use the same one, if you think it will be more convenient and have the financial means then get what accommodates your needs.