I would suggest using a framework. If you hand spin your own code, it could cause more headache than you want to deal with. Hand-spun code requires that you build your own "framework" of sorts anyway. Basically, you will be building everything from scratch that a framework already provides. Not to mention, your code will most likely be way less organized (and structured) than a framework. You will also have to deal with security issues that a framework may provide by default. Most frameworks are plug-n-play so to speak. They do all the grunt work for you and you get to focus on writing the application, not having to worry about all of the basics that typically go into every app.
I would advise using a framework and here is why:
- You will be forced to use good coding
practices right out of the gate
- The code will be organized and
provide for easier extensibility in
the future
- Delivery time of the app will be
significantly reduced
- It provides better structure for
multiple developers to work
simultaneously
While there may be a OOP learning curve, you are better off doing things the proper way from the beginning than trying to reinvent the wheel in a functional way.