For the last two years, I have been using something like this: a reversible grill/griddle combination that fits neatly on my Coleman stove.

Mine has much more raised ridges than this one; mine are about 3/4 inch high on one side and a flat griddle on the other side. It covers the entire surface of the original Coleman propane stove.
I just got tired of trying to fit the extra bulk of a BBQ somewhere. I just store this in a side compartment in the bed of the truck in a plastic trash bag.
I'm NEVER without my Coleman stove, as we cook 95% of our meals outside in our outdoor kitchen setup.
I have owned a few Magmas; mostly the round kettle ones for boats. My beef with them is that their LOW setting is still so high that's it's hard to slow cook anything.