reasonably successful? Losing 40%points in market share is success? I am of course talking about the full Symbian time line not just currently
Do you have a source handy? It would be interesting to see how Nokia's market penetration (however declining it may be) compared to Microsoft's.
But Nokia dropped far less (47.6% -> 37.9%), proportionally, than Microsoft (8.7% -> 4.2%).
No question that Microsoft is the winner here.