I am in exactly the same saga as your right now. Our DD just turned 2 in September and our son will be born in May.
We currently use the Mountain Buggy as it is simply the best pram out there for a comfy rid, room and durability. Mind you we do a lot of walking and camping so i just love it. After seeing the new MB +1, i nearly cried because its horrible! No child will want to sit in the back. Then i looked at the Phil n Teds which is still a good pram with the pump up tyres and the ability to take away the 2nd seat when the oldest child just wants to walk, etc. We also had a look at the strider plus. This pram is a great pram. Its big and roomy, is so simple to use, its not cramped at the back like the others. But the only down fall for me was that it didnt have pump up tyres which made it a fairly crap ride for the kiddies. The only other factor was that it simply didnt fit in the boot of my car. Soooo, the Phil n Teds it is for us i think.
Im going to sell my MB on ebay and use that money to buy a 2nd hand Phil n Teds on the same site. Im not going to fork out another $700 odd for another new pram!
The other option of course, is the side by side pram. Clearly, it would have been the Mountain Buggy again, but i just cant fit it in the car!
All our friends have Phil N Teds prams. We've all travelled to Bali with them and they were great. The kids slept fine in them and they handled the streets well. They fold up nice and compact and will fit in practically any boot.
....im still so annoyed at Mountain Buggy for totally destoying the new +1 pram.