As far as I experienced you should choose between alternate layout or responsive layout.
If you use responsive layout with breakpoints there´s no reason to create alternate layout. You could do it in just one step.
Alternate Layout has fixed all widths. No breakpoints necessary.
Responsive layout is also better for SEO, I heard.
P.S. your link does not work.
That´s the correct address:
Thank you very much for the clarification Uwe. Do you know how I would test for mobile and table compatibility if I only have a responsive design layout? Besides the obvious of having to check on every current device. Thanks.
Well, with responsive design you don`t really necessarily decide between desktop , tablet and phone versions.
You just use this grey scrubber on the top right hand side at the breakpoint bar and move it.
As soon as your design starts to "break"/"bleeds" outside the canvas you add a breakpoint and adjust your elements
as desired. It is good practice, while doing responsive design, to start with fixed width breakpoints.
What I do normally.with Safari there´s a tool called "Developer", I check responsive design.
All this beside the test on real devices.
There´s also one from chrome, which I forgot the address. This one from chrome has more devices in its case to test, but also – real devices are necessary to test.
I started to watch some DW tutorials and realized, they go with alternate layouts kind of mixed with fluid width breakpoints.
So this might be a difference between those two but important to know, I guess.