hi - dont know if this helps or hinders decision making but this is my experience.
DS1 was 2 yrs and 8 months when DS2 was born. He is tall for his age but normal weight. Although DS1 walks a lot I thought the twice daily nursery trip might be too much for him - its about a mile to get there.
I'd bought a P&T's E3 (2nd hand but still v expensive!) beforehand, and also a Bibi Swiss Strolli Rider from ebay (also 2nd hand but still £50) Never thought he'd like a buggy board much.
I probably wouldnt have bothered with the Phil and Teds if Id known a) DS2 was going to be such a whopper (10lb 3) He didnt fit underneath for very long, and now we've had a long gap where we couldnt use it because at nearly 6 months he's still not comfortable on the double seat as its too upright for him ( I got a sport reclining seat for him and whilst thats better than the original seat, he's still uncomfortable in it and cant nap) So either DS1 walks or it stays in the garage (itt stays in the garage!)
Also in the winter, DS1 was too tall to use the hood/raincover, so it sort of sat on his head. Not terrible comfortable for him.
Now he's a bit older (was 3 beginning of March) he doesnt really need a buggy, but I use the strolli rider cos he's lazy and he loves it.
I wish I'd just stuck with this in the first place. The only issue with it is its hard work on the pusher if the paths arent particularly even where you live. I find though that he stays sitting on it because he likes the idea he's on a bike. It fits both our hauck infinity - which was great when the baby was little because it had a pram attachment, and still is now I've got the buggy seat on - and on our silver cross pop ( which I find more stable with the strolli rider - possibly because it has hard wheels not air tyres. )
In summary, the P&T for me was a waste of time.