There was 17 months between my 2 terrors. The baby was born nearly a month early and was tiny, my son was huge!!!!
The first double pram I bought was a Graco tandem with a car seat for the baby. This was ok on the flat with no kerbs to go up, but with my large toddler in front I had trouble going up kerbs and the amount of people I ran down going round corners was embarassing. Plus with the baby being so small I wanted her to be comfy so never used the car seat on the pram. My mother couldnt steer it or again get it up kerbs
The next one I bought was a Mamas & Papas double - the old side by side with 2 carrycots and/or 2 seat units - this was perfect !!my little girl could lie in the carrycot and I could see her - my little lad could face frontwards and not get at his sister - the only draw backs was it was a bit bulky but IT did fit in an escort and that it was too wide for a lot of shops - but by far one of the better ones I have had
I have had a Graco - side by side - an ideal compact pram for 2 little ones - my son could not get comfy in it because of his size
Then came a Maclaren twin - but the frame broke on my sons side
A cosatto kiwi double - again listedover the side my son was sat in
A bertini 905 - ideal as only the width of a single pram - perfect for the early months BUT - bad weather and a toddler in the toddler seat not very comfy and warm and then when the little one in the back wants to sit up - they cant
Bertini shuttle and a toddler seat - again ok for the first few months but beware of the handle and a chunky toddler - they do start to give
After trying the bertinis and loving the way they steer - I bought BNIB bertini 906 Twin - a bit crammped for my son but he did walk alot so thought sod it!!! perfect until again it started to list and the wheel kept coming off
After all of this my son started having problems with his hips because of the ligaments -(one of the reasons he didnt walk too far as it hurt him) so did my homework and bought an easylife double - heavy to lift, abit heavy on the steering but perfect for both - little girl was now 12 months old,so again bought one new - and it did makemy life easier.
As new prams are so dear, and beleive me I have had 5 new double prams - my advice - dont buy the "new must" have pram because of style,colour or name - get one that is suitable for your little ones and you!!!!
If possible try them out (pinch your friends, sisters,cousins etc) if not have a look on ebay buy one cheap enough that if you dont like it - you havent wasted alot - ask questions then ask some more - sellers shouldnt mind but beware some might not be totaly truthful i.e i asked over an easylife twin and was told it wasnt very heavy and fit in a peugot boot - a small peugot at that - it weighs about 17kg and to make it very small you have to take all 4 wheels off - not ideal to go shopping then spending 20 mins trying to get the wheels on!!!!
If you have any questions please ask and I will try to answer them