I agree that, with time constraints, Mandalay is the stop to eliminate. We found that the combination of Yangon, Bagan and Inle made for a nicely balanced trip. We stayed at Inle Princess Resort and found it more rustic than anticipated but beautifully sited. The Aureum Palace in Bagan built a tower that actually rises above the various temples - it got my blood boiling every time we passed it. Power corrupts, indeed.
Balloons over Bagan is a great way to get an overview of the area. It doesn't operate year round, however. If taking photographs is important to you, be sure to avoid the side where the camera is mounted....otherwise, you will have a wire in many of your shots.
We were wildly disappointed in The Strand, but loved Governor's Residence.