In my shop there are basically four levels of work station. The lowest of the levels is my new saw bench (21 inches) and my old "Box". The Box was build a years ago as multi-use item. The Box is 9 1/2 x 16 x 19, I made the box to stand upon while working in the basement. I also made the box tight enough to use as a dust collector, there is a vacuum port in one side and many holes drilled in the top. The Box very nearly matches the height of the saw bench to support longer boards when I am cutting.
I made the saw bench two weeks ago and have used it several times, when I have a small job and don't feel like all the noise and dust.
The second level of work space is my heavy duty work table (34 inches). I have talked about it before, it is on locking casters, very heavy and equipped with a vise and clamping points for KREG Clamps
The next work space is my KREG Clamping table, ( 36 inches) I have raised the table to its full height and put storage underneath. The Klamp table is used for assembly of small work and painting. I covered the top of the clamp table with 3/8 plywood to protect the top from stains and glue.
The tallest work space is my carving bench. I added this second section to my small bench recently to raise it to 44 inches. I find that I have less back pain when I stand up very straight as I work at a bench or my desk.
It has been almost one year since I was felled by a herniated disk in my lower back and I have been doing everything I can think of to make my work space 'back' friendly. Having various levels upon which to work and being flexible about how long I work has enabled me to keep making sawdust, which makes me a happy guy.