We operate a web application that is about to get two big updates. One is styling; although all fields, buttons and elements stay in the same place, the application will get a big redesign. The second is a performance upgrade. Certain frequently used parts of the application became slow over-time, and that'll get a significant boost as well. (Performance is something our customers tend to complain about.)
Both updates are ready. We just have to launch them.
What yields the best response? A major update at once or two significant ones in successive weeks?