I have the J&L one on my 5.0. Added it around 1K miles.
It's not as necessary on the 5.0 as it is on the 3.5EB. Some people have found considerable amounts of oil in their inner-cooler (not as common) but it's a real issue.
We have port+direct injection which cleans the tops of your intake valves. By adding a catch can you're keeping oil out of the intake-runners and ports completely, which overtime can help the engine breath and keep the top-end clean.