That's kind of a hard question to answer without knowing your definition and requirements for 'web development'.

First, keep in mind that some of the packages will simply not run on FreeBSD because it's often overlooked by developers. Same logic applies for technical support for applications that are running on FreeBSD powered machine.

You also will need to learn how port system works on FreeBSD and it might be a weird learning curve. Same applies for kernel patching/upgrading/etc.