For the neck lanyard, I prefer a breakaway although several of the items I carry are on a pretty strong breakaway.
My main compass (at work) is a Brunton Pocket Transit (large and heavy). It rides in a pouch on my left hip. When I am in the woods for fun, it is usually an old Silva in my pack or around my neck as conditions dictate.
I use lots of neck lanyards, one (through the collar of my shirt (button down)) for my hand lense (magnifying glass) - which goes between the first and second buttons in my shirt, one for my binoculars (Leitz 8x20) - goes between the second and third buttons, the third for my camera (in the right pocket) and (depending on terrain and conditions) my compass or altimeter (left pocket). Different colors, materials and destinations keeps them apart and functional. I don't like things dangling on my chest. For those who must ask, the space between the third and forth buttons is for my field book, while I am doing something else - not for general carry.
Like Hikermor I seldom use a compass for navigation in the Rockies or Sierras (I do use my altimeter there, on a lanyard around my neck), but lots of terrain (Great Plains, arctic tundra, glacial ice, flat woodland, etc.) and weather (blizzard, white out, fog, etc.) requires the almost continuous use of the compass. Canoeing in places like the Boundry Waters requires one to use it frequently (although I often tie it to the canoe in this situation - with the lanyard). All these situations make the lanyard - around the neck or tied to something handy - a very useful tool.
The neck is a good place in my opinion, but it must work for you. Many of my tools are on lanyards attached to their pouch or pocket as well (usually tied inside). This keeps the item attached but keeps the lanyard out of the way when not in use.
Respectfully,
Jerry