I should check the actual weight of the RRS L bracket for my 1D IV.... I just did, however the L bracket for my 1D IV is out of production. The weight of the two part L bracket for the ID X Mark 2 is just over 9 ounces. That surprised me a bit. I don't believe any of my one part L brackets are that heavy. I just checked Kirk and as I thought, their one part L brackets are only 6 ounces.
Anyway, I use both a monopod/tilt head and tripod/gimbal head when shooting wildlife photographs so I keep my L brackets attached. I've grown accustomed to their presence. I don't even notice the extra bulk or weight. Since I attach my shoulder strap directly to the L bracket, it has that additional function as well.
I switch out the gimbal for a ball head when doing landscape only stuff but my gimbal does an excellent job when shooting in the landscape position: it is a tad cumbersome when shooting portraits, hence the change to a ball head. I have my tripod set up for a quick change for both heads: it takes a few seconds to switch.
Kim (the male variety) Canon 1DX2 | 1D IV | 16-35 f/4 IS | 24-105 f/4 IS | 100L IS macro | 70-200mm f/2.8L IS II | 100-400Lii | 50 f/1.8 STM | Canon 1.4X III
RRS tripod and monopod | 580EXII | Cinch 1 & Loop 3 Special Edition | Editing Encouraged