I mostly agree, on paper the bee is exactly the pushchair I want.. yet I don't want it. I'm still not sure it has any direct competitors though.
I think sub 10kg with stroller board compatibility is do able. Oh, not with an iCandy though, put a buggyboard on your warranty has flown away. Even if that wasn't an issue tbh they're not best suited to them anyway imo.
Now I have questions - do you plan to follow the same pattern when it comes to getting it upstairs? Ie carry the cot/seat, then the base after in another journey? The reason I ask is with two kids that gets more complicated but certainly not impossible. The bee of course has no carrycot and folds in one piece not two. I'm trying to work out if this would help of hinder you with a baby and a toddler in tow?
Also is size of the open pushchair a major factor? The things the bee has going for it are the combination of all in one fold with seat facing either way, small dimensions open and a generally neat, if boxy fold. If the open dimensions are less of an issue then you will have more options, there are very few pushchairs narrower than 56cm that have a parent facing seat, some but not lots. circa 60cm wide there are loads.
One of my current favourites is the Baby Jogger City Versa, it has a nice all in one fold when you use the seat unit, obviously not with the carrycot. I believe it is over 10kg though, not sure I would want to carry it up and down stairs multiple times a day. I have used a buggyboard on one successfully though so I know it ticks that box and is easy to push and use, huge basket, big seat, massive hood etc.
Right now at this moment in time if I personally was having another baby I would probably buy a brand new and totally unproven Silver Cross Wayfarer I like it better than the bee, it has the same open width. I'm obsessed with width though, it's my thing. Only folds forward facing but has carrycot and gubbins included in price, frame is v light, it's easy to fold etc.
Other things to look at:
Babystyle Oyster - this has a really good reputation with the buggyboard but a less good rep overall for faults etc.
New improved June coming summer 2013, the faults with handling and lifting the front are apparently dealt with on the new model. If this is really true then woohoo... I'm waiting till it actually really happens and I see with my own eyes.
New Maxi Cosi/Bebe Confort Loola - I saw this recently and unexpectedly LOVED it. Massive lie flat seat, great fold with the seat in either direction, fine to handle, easy to tip for kerbs etc. Should take a board, the old ones did anyway.
A big list of other stuff I have forgotten and will hold off until you specify a size limit! 