I have room for one or the other in my home 'gym' - either a functional trainer or a standard style home gym type machine. I already have a very nice elliptical (for me) and treadmill (for the wife).
Indiatimes: Why men and women are ditching the gym machines: Rise of functional fitness
Why men and women are ditching the gym machines: Rise of functional fitness
The modern technical definition of a functional is a function from a vector space into the scalar field. For example, finding the length of a vector is a (non-linear) functional, or taking a vector and returning the 3rd coordinate (relative to some basis) is a (linear) functional. But in a classical sense, functional is an antiquated term for a function that takes a function as input. For ...
Furthermore, a formal analysis of the Taylor expansion of the density functional for an interacting electron system at finite temperature is given and the relation between density-functional theory and the field-theoretical approach to the many-particle problem is enlightened.
In my undergrad, a first course in measure theory was offered alongside a first course in functional analysis and this seemed to cause few problems. The prerequisites for measure theory were (primarily) a good grounding in real analysis and the theory of metric spaces. For functional analysis, confidence with real analysis and linear algebra should be sufficient; familiarity with metric and ...
It is a nice read for someone with only an undergrad analysis course. My favorite, although you might have trouble with your background, is Applications of Functional Analysis and Operator Theory by Hutson and Pym, if you can find a copy. I learned functional analysis from doing quantum mechanics and then read all of the above books.