Loading a large wallet (around 23 mio transactions here on test) is resulting in an unusable GUI. Spinning wheel of death on every mouse click for 5 seconds at least.

branch: master
OS: macOS 10.14.2
CPU: Intel i9 (8th Gen)
RAM: 32 GB DDR4

Note: this behaviour is not limited to the Overview page or CoinControl but in general as long as the wallet is loaded. A headless setup performs nicely though.