If you need a side by side comparison for MongoDb and Cloudant, you can find it here:

http://vschart.com/compare/cloudant/vs/mongodb

Here to answer any questions if anyone has any. James

You say you evaluated Cloudant and MongoDB, among others. Why did you decide on Cloudant?

-Recommendation by the Windows Azure team. -Scalability. -After I got my head around CouchDB in a weekend it was so easy I didn't need to look any further.

I used the documentation on the Cloudant site over that weekend so that definitely played a large part too.

High level -- what's it like writing for windows mobile vs iOS/android?

I've only just started developing for Android (Foundbite's next version) so can't really give an opinion. Visual Studio is great to work with though. There are only 4 screen resolutions for Windows Phone so in that sense it's easier to develop the UI.

How does Cloudant compares to Azure Table Storage ?

Azure tables is good for storing data much in the same way as a spreadsheet, however when you want to do anything even slightly complicated to index the data it soon becomes hard with table storage and you have to start repeating data. Not ideal. Cloudant makes it very easy to store the data and index it in a myriad of ways without repeating any data.

While I agree on limitation of indexes - you get 3 - table name, partition key and row key, you can 'nicely repeat data' by embedding it via serialization.

I ported my db from mongo over to storage tables. I was embedding data, so I didn't have to do two lookups, and when I moved over to storage tables, I wanted the same thing, so simply serialized via protobuf - works a treat.

Interesting, certainly clever than the way we were trying it.