I use the CakePHP framework and it's really awesome. There is a learning curve involved (I'm still learning), but it's definately going to be a huge timesaver.

The MVC design pattern that was first introduced by (smalltalk?) has been re-popularized by RoR.

What do you think the pros and cons of developing with the MVC framework are?

I like to learn the proper stuff, but if it works for you, great. I think that is a con: once you've started using a framework, there's no going back.

I like the avoid frameworks, they seems like extra learning

Though, I have written a load of functions I tend to keep reusing (like mysql communicators and timestamp mediums).

That's what you gain, writing functions, for a decent time, isn't it?