You will find that many modules that were in the \xampp\php\ext\ folder of XAMPP 1.7.3 are no longer there in 1.7.4.
As a result, a lot of PHP functionality that used to be there in 1.7.3 is no longer available in 1.7.4.
Also the Microsoft .dll for accessing MSSQL is no longer there in 1.7.4.
And to add to all this, it seems that the XAMPP control panel is no longer able to start the FileZilla server without registering it as a service.
The XAMPP control panel in 1.7.3 can do that.
Should I continue?.....
My personal opinion? ... Stick with 1.7.3 if you can!