They allow a good balance between a heavy load and a good stretch. Close Grip Bench Presses are a good mass/strength builder... and rope extensions would be a good all around strech movement for full-range mobility.

I prefer skull crushers with a cambered bar on a slight incline bench... this gives me a good range of motion while allowing me to preview my form with a peak at a mirror. Letting the bar go behind my head and not using collars to insure both arms keep there end balanced - otherwise the weights fall off!

BTW - I have to step load this movement to protect my elbows - to give them enough of a warm up. I will add 20 pounds - then subtract 10, add 20, subtract 10... moving up to the desired weight...

Not using collars is a personal preference. If you can control the bar it will help force you to keep it parallel with the ground. Make sure you remind a spotter so if they grab the bar after the completions of a set - they know to hold it parallel too. I handed off a cambered bar with a 45 and a 35 on each end to a spotter after finishing a set yesterday, and it fell apart on him... he was kinda pissed about it... Prolly not a good thing to recommend...