I've spent hours a while perusing the threads about the BJCM, and the more I read, the more I want one!
I saw one in the flesh for the first time on saturday, had a play around and loved it. But at the time I wrote it off because I want a pushchair I can plonk the carseat onto for the school run.
Then, when looking again on t'internet, I found that you can get adapters for various carseats and there's a carrycot available too! 
So, decision made.
However, I was wondering if anyone here who has/had a BJCM has used it with a carseat and/or the carrycot, and if you can let me in on your experiences before I finally take the plunge and order one.
TIA [busmile]