Its not a monster, its one of the slimmest side by sides on the market today. ;) Unless you import from Canada, its also the only stroller that can do what it does.
The seats are small and I wouldnt buy it for a 2.5 year old. I bought it for my multiples because I knew I would get the best use of it from birth. I think its an AMAZING twin stroller or for children very close together. I wouldnt get one in your situation.
Overall though, its incredible.