- Repositioning the cursor by incrementally searching for the word you want to move to is more accurate, quite fast (3-4 letters is virtually always sufficient to find the word in question), keeps you in the text / document "head", and leaves your hands on the keyboard.
- Yank (y) + movement (w for word, ) for sentence, } for paragraph, 'yi<modifier>' for copy within marks (quotes, braces, angle-brackets, parenthesis, etc.) is also amazingly fast.
- Visual mode can be used to select specific blocks of text where necessary.
- If I want to select specific fields from a file, I'll usually either use tools for that purpose (cut, sed, awk), or read in the entire file and edit it down from within vim. The tools-based approach means I can reproduce the task readily if I need to do it repeatedly.
And finally, where I'm dumping text from some GUI app to vim ... it's still usually easier, faster, less error-prone, and more reproducible to grab the entire screenful of text without specifically selecting what I want (e.g., C-A or Cmd-A (Mac)), and then trim to size within vim. Again, vim's tools permit working with text as text rather than with text as a GUI presentation.
I'm not saying I never use the mouse for text selection, but it is far less common than you might think, and much more cumbersome.