I'd definitely use it more if I could port over the last few Delphi apps I have in production. My Delphi 7 is getting a bit old...
Aside from single-file executables, the biggest advantage to Lazarus (and also Delphi) [to me] is that all the libraries are also built in the language. No needing to bounce down to opaque DLLs just to display some GUI element.
Shameless plug: if you think you are up to the task and is not too expensive contact paulo at xtend.com.br
[1] http://acbr.sourceforge.net/drupal/