Here are some things that i think are a must for a programmer (php in my case) and are not implemented or not user friendly at all.
1. No proper hints for function autocomplete.
For example, when I write the starting letters of a function, hit ctrl+space for autocomplete, the dropdown with multiple possibilities appears. So far the only possibility to see some details of what each function in this dropdown actually does is to hit ctrl+q and to activate the documentation. Seems rather frustrating to hit multiple times in order to see a simple hint.. my advice is a hint row should be put under the dropdown to display a @desc for each option (see PhpEd).
2. No proper hints for function parameters.
Basically you want to call a function and when you get to write the parameters… the only hint you are given is the param name used in that function, nothing about what type of parameter it should be. It would be indicated that in front of each parameter name it's type to be dispalyed.
Moreover, I write a function, for example doSomething(), and if i put my cursor inside the brackets and hit ctrl+space to get some auto suggestions, I should get a list of the expected parameters that my function requires, not some not needed variables. I'm hitting auto suggestion inside the function to get a hint of what parameters i need to fill in, no others should be displayed instead of the ones my function requires.
3. A vast majority of php programmers use the help function (F1 or any other shortcut key) on a function to open an internal web browser with the help from php.net.
Hope ot see these features in the final release.