Actually... for me ... using the in game Windowed mode is faster then the third party Windower. And a lot of people who use the third party Windower app just leave it set to the default settings and run it in a Window sized at 800x600.
There are some negative things about Windower... for example it's setup to load some plugins automatically at start up. Unfortunately... they may cause the game to crash. This was a problem when Windower was being distributed with an out of date plugin which crashed the game every time. I assume the problem has been addressed.
Also the original person behind Windower left a LONG time ago. As did the people he left it to originally. There will come a time when development no one wants to bother (unless they open the source code to everyone and they seem very reluctant to do this).





