Hello
Im a nanny and use the phil and teds for my 18 kg 3 year old and 12.5kg 13 month old charge
all i can say is the buggy is GREAT... i cant sing its praises enough.... even with over 30kg of child i can push it SO EASILY with one hand ... (much easier than with just the 1 year old in his mamas and papas 'nice' buggy, or the maclaren techno xt!)
its also brilliant cause it can be a single (GREAT for our nursray run, so i dont look silly pushing a double with only 1 child in it!) and in a few months when eldest doesnt use a buggy at all its still a really functional go anywhere all terraince single buggy!... as good as any other 3 wheeler ive ever used including the top of the range mountain buggy!)
with a new born in feb you will (IMO) definitely need the cocoon, as it will be cold and you will know that the baby is all snuggly. (while it may not be 'as essential' in the sumemr when its boiling hot its mich easier to get them in and out regardless...
also my car has a small boot but its not a problem cause the wheels click on and off SO easily!
IMO you 'need' a phil and teds and will have no regrets if you purchase one
as for panniers, we dont have them but i REALLY wish we did... cause now they are both a bit bigger their feet effectively go in the 'basket' so you cant really use it when the big one is in there cause his feet fill it, or when little one is in there cause he manages to touch everything
i LOVE this buggy and as and when i have my own kids plan to get it straight away for the 1st one... (along with a Maclaren Volo)... IMO those 2 buggies see you through anything and everything!