Agreed. If anything performance seems to be worse with the change from SVG graphics. Now when you zoom in inside a room the whole page stutters to a halt in chrome. I'm running an r9 280X and 3570k so those aren't the issue and this wasn't really a problem when SVG was in use.
The map view is also pretty bad with larger window sizes. Having the window set to 1440p, it takes about 5 seconds to load all the rooms in the map and just panning around is incredibly slow.
Strangely, firefox seems to have better performance at room level but worse at the map since it freezes the entire window until every room in view is loaded.