could you please tell me your opinion of the pros and cons of each, practically speaking?
My dd is now 7.5 and has nearly worn out her Mac Major, so we either need a new one or a wheelchair.
She has an odd, inefficient gait, is generally weak, and tires easily when out. Her strength is improving recently and now we occasionally venture out without the buggy. But even at this rate of progress I expect that until she is over ten, maybe older, she will need wheels of some sort, for longer outings at least.
The problem is tiredness, so she wouldn't be self-propelling. She's quite slouchy in the buggy. (Well, everywhere really!) I don't feel she needs any more support than she gets in the buggy, but she's likely to be unhappy if she has to sit very upright, cos she'll just slump over sideways - are basic wheelchairs quite upright?
There are no behavioural issues to consider. Dd is tall and skinny and doesn't look to be outgrowing the Maclaren Major any time soon.
Our estate car has a big boot but I want it to go easily in there. I need to carry it through the house easily. And being able to fold it well for when the bus is crowded would be good.
Which is easier to push? It's all city streets, up and down kerbs etc. No fell walking for me 
I don't think I am too bothered what any busybodies in the street may think of a child in a buggy or wheelchair, and dd is pretty oblivious to that sort of thing, so I'm really just thinking about practical considerations.
Thanks!!