If using a table based layout you have to type
    many many more characters and keep a mental
    log of what's in where.

Not when generating HTML via a program. It's trivial to generate complex recursive nested table layouts that reflect/mirror the structure of the underlying data.

Honestly, understanding how to use floats and clears properly is one of the hardest "computing" concepts to learn out there. First of all, they're a completely non-intuitive way of structuring layout, and secondly, they can break in 1000 different ways if you don't know exactly what you're doing.

For anyone who doesn't do CSS professionally, tables are vastly easier. They're easy to understand, and generally do what you want.

It's just that, as time goes by and your site becomes more and more complicated, tables become less and less flexible and maintainable.