I’ll chime in with my experience. I ended up ordering a Kirk base plate at first, which is excellent and provides a good bit of coverage across the bottom of the camera. But when Promedia Gear released their design for the L bracket I jumped on that.
The Promedia has an offset design to the vertical L which makes the screen and cables completely free and clear of the bracket. You can move the screen unimpeded. They sell an accessory which clamps any cables to the bracket to prevent them from being yanked, even though the bracket is over on the side.
The forward set vertical provides some unique protection to the first third or so of most lenses as well as, to a lesser degree the camera itself. If you’re ever frustrated that your AF and IS switches on the side of the camera get switched off by your clothing, that problem is gone with this design.
There are pros and cons to the handling. First, the vertical makes for a very nice handle that you can actually wrap your fingers around. Whether you’re pulling the camera from the case or swinging it at your side, you can fully close your fingers around the bracket like a suitcase handle. You can also hold the bracket in your left hand as you shoot, if you don’t need to have your hand on the lens.
Changing a lens is a little weird. The bracket is right in the way, which could be a deal breaker until you realize you can push the lens release through the hole on the side of the bracket. It takes some getting used to but it works.
This bracket comes with a storage cost. The camera will not fit into it’s normal slot in your bag or case due to the added bulk to the side of the lens and the added width. (See red marks in image above) I’ve found that to store the camera with the bracket on, I have to reconfigure nearly every bag I own, eliminating space otherwise used for an extra lens.
One of the best features is that the bracket is modular and the L can be removed. It has chunky robust steel rods that connect to the base plate, which is probably the most solid connection I’ve seen. It also allows you to slide the bracket way out and screw it tight, which allows you to have a “wide” handle or even use the cold shoe on top for a flash bracket.
There are also tons of accessories for the Promedia. I’m looking to get the Spider Holster style connector, which screws to the side of the base plate and allows you to use a pin that slides into a spider holster. Also they sell a crazy flash bracket and lots of other accessories. They now offer either a QD socket or their proprietary SS2 socket for strap connection.
Overall, I’m kind of lukewarm on this bracket due to the bulk and storage challenges. I keep the vertical detached often, but I’m missing the additional base plate coverage (the baseplate is really small once you detach the L) provided by the Kirk.