does anyone know of a matrix that would show the functionality differences between different versions of SED?
like some versions you can't use '<anything>+' for one to many occurences of anything.
I thank you in advance for you time and help. 
Check the sed FAQ.
You need to look at Jeffery Friedl's 'Mastering Regular Expressions' - see Chapter 3.
If you are really pressed try GNU sed - part of the GNU coreutils distribution. Stick with that if you can.