I bought a trap bar about 3 months ago. I spent a month before that agonising about whether it was a good idea, reading every forum post about trap bars I could etc. There's no gyms anywhere near me that have one so I couldn't try before buying.
At first I didn't like it much. Used it once and put it in the corner to collect dust. More recently though I've grown to really like it...... because;
* I can do a heap of concentric only lifting with it after squats or front squats. I use it every session now to beef out volume without trashing my nervous system
* I can do concentric only lifts without learning oly lifts or having a platform and bumpers (I'm learning them... just slow)
* I can get into a pretty upright position by pushing knees out, ass down and get decent leg volume after my back is stuffed from squats
* I can flip the bar over and get more ROM, just above paralell squat depth
* I can just drop the thing on grass
* I can also use it for more hip dominant pulls by standing back in the diamond a bit
* Its good for shrugs etc as well
* I have a few complete novices who come to use my home gym and even they can do compounds on it
I won't ever use it as my primary lift.... but its the best secondary out there for me
That is all