Fatty's are solid across the top and connect with 2 u-bolts. Simple, yet sturdy. I haven't had any issues at all and love the solid feel. I have switchblade highway pegs mounted to the outside of them (5' 10" ) which fit me perfect. I also have the leather lower bar covers I use in either wet or cold weather.
I have the front fender rail (Showchrome) that attaches only to the fender mounts (not the front). Others have reported cracking after a while, but mine have been fine with no vibration or noise.
I highly recommend the Cobra Fatty. It's solid and nice. I'm also watching these brackets
on ebay to mount some touring lights. They would fit well with the Cobra Fatty bar in 1-1/4".