This is a comparison video I just made of the same project opened on Version 14 and Version 15. All I am doing is opening the project then opening the Pan/Crop window. Notice how the P/C window opens quick/snappy in V14 but in V15 it seems to do a second/third refresh before displaying the window. This issue gets worse (the delay between the multiple refreshes and then display to the screen) increases the longer I work in Vegas 15.
Do others see this same thing? This issue makes V15 pretty much unusable for me aside from a renderer (work in V14, save to temp .VEG, render out that .veg in V15 since it's much faster in that regard).
I wish there was a legacy GUI option. V14's GUI w/ V15s under the hood/rendering improvements would have been perfect for my workflow. Version 15 is very frustrating to use because of the performance of the new GUI.