Thank you technonath1, for your list:
I have tried to put together a list of all the gaps and missing functionality. it is just compiled from comments in various threads and may not be entirely accurate.
Feel free to edit it, improve the categorisation, update the list of delivered features or Due dates for known coming features.
https://docs.google.com/spreadsheets/d/1E3YpIx7-eYav96Rbs65R1AX6THweicHrGntFzqdNeXQ/edit?usp=sharing
I have added "Cannot set incoming plain-text message to display as fixed-font" to your list. This is quite an important feature for our organization because we produce a large number of columnar format reports for our internal users, and they are not displayed in a fixed-width font like 'Courier New', then the reports are a jumbled, illegible mess. It may seem like a minor feature to the MS designers, but this is a major issue for us. They need to broaden their focus groups (if they have any) before they foist a change like this on the community.