Yep, that's certainly true. One nice thing about tags, though, is that they can span an entire project (whatever files you specified for inclusion in the tags file). So you can move the cursor over a function invocation, hit "ctrl-]", and jump to the definition of that function, in whichever file it lives. Hit "ctrl-T", and you're back where you started. You can search on tags directly as well, making it easier to grok large, unfamiliar bits of code (the taglist plugin really shines here).
The search function in VIM is very robust if you know what string to use.