Not twins but two babies with only a year between them, both still very small, requiring naps.
Pros:
Its narrow and you can function on the pavements / going in and out of shop doors and so on.
As long as the tires are pumped up, its easy to manouvre around, up onto curbsides, round tight corners.
The handlebar is adjustable to quite a wide range. Its also spongey so you don't slip if it gets sweaty
You can get quite a lot in the underbasket, small stuff like blankets, extra tops, a couple of bottles and nappies - sort of packed flat as it were. You can do this even if a child is sitting in the back. But you can also get side attaching panniers (not so easy to fit and tend to drag / catch under the wheels).
The sun cover and the rain cover are both excellent and fit very well (once you've figured it out)
Cons:
It can tip if one child is still in the back and / or you have a bag hanging over the handlebar
Neither seat can recline for sleeping when they're both in it. Front seat can recline far, but not if someone is sitting in the back - or they'd basically get squashed flat.
That means their heads slump forward onto their chest if they fall asleep, or they're resting their head (front seat) on a bar with no padding.
I put extra seat covers in mine to make them more comfortable. You could get a neck rest / travel pillow (not sure what age these are ok and safe).
I couldn't live without my P&T but I do curse it, daily.