In the new version, Xcode’s code completion has improved slightly, it shows suggestions while typing even if spelling is worng, etc. But, in some cases it is slower, for example: when a custom class is just imported, it doesn’t show up in code completion.
Also, I presonally prefer the look and feel of old Instruments.
The Other issue, is Xcode keeps giving un-related errors, specially when one line of code has an error –like an incomplete if statement– then you can see a bunch of other errors show up, completely un-related and redundant, just because of a missing brace a few lines above them. This problem has become worse in the current version.
A really annoying problem that we were experiencing for years, and it persists version after version without fix is: the iBeam Cursor on dark editor background is invisible. The woraound is to replace the iBeam Cursor image manually, which should be re-done after each upgrade. A white cursor with a black border is visible on both dark and light background. I don’t understand how making a more visible cursor seems to be so difficult for Apple!