There are lots of different L-Plate manufacturers out there but only few create L-Plates designed for specific cameras/lenses. The real advantage of having L-Plates that were designed to work for a specific piece of gear is that these plates just can be seated on the body/lens as if they where designed by the lens/camera-body manufacturer. In fact the lens plate replacements are usually even more robust and stabilize the lenses better on a tripod than the lens foot of the manufacturer. Nikon had always a very bad reputation when it comes to lens foot stability. Most of the third party lens foot replacements for the very long tele lenses do a better job than what Nikon provides. There are no tolerances that allow these L-plates to move even a micro-milli. Everything sits tight and locked down – even after weeks or months of hard use. The installed L-Plate just always makes me feel more comfortable and setup for everything that comes down the road. It secures the camera in the case of a fall, I can always put the camera on a Arca Ball head immediately and … – this may come as a surprise – I like the additional weight and size of the camera! It gives some more movement inertness to the whole system that I like – especially with medium sized lenses. With very big lenses the additional weight is also welcome since the balance of a heavier camera body is much better with the large lens boys. Here I clearly do not understand the discussion around smaller and lighter cameras – I dont want a smallish and light camera, I want it big and heavy – it lets me create shots with more acuity and makes the camera/lens combination more usable/better balanced in various situations.
This precision of camera/lens-specific plate designs comes at a price – these L-Plates are usually in the range of 200 to 300 Euro each, but you get what you pay for. I usually buy new L-Plates with every new camera generation and leave the L-Plates on the camera bodies and do not remove them anymore. The Really Right Stuff L-Plates also protect the camera bodies from damages when you drop a camera. Its overall a great extension of the possibilities and you get Arca Style compatible L-Plates that fit to every Arca ball head in hori and vertical position.
There are two L-Plate manufacturers out there that need to be linked here: Its ReallyRightStuff and KirkPhoto. Both these manufacturers produce excellent custom designed L-Plates for all kind of photographic gear. The L-Plates fit exactly towards the specific camera body base – its in fact precisely a negative shape version of the camera body bottom shape. I believe quality of both manufacturers is comparable but I tend to buy from ReallyRightStuff but its likely only a minor personal preference – KirkPhoto seems to have the same standard of precision and quality.
All my long tele lenses have an RRS plate attached and I also have L-Plates attached to all my camera bodies. I dont attach L-Plates to the camera+battery-pack combos because the battery-pack is clearly reducing the tripod stability and creates a weak spot for mounting the system on a tripod. The new RRS L-Plates feature an additional screw at the strap-fix position that allows the L-Plates to be also effective with the MB-DXX battery packs on Nikons but I havnt tested these so far. But they are likely also improving the stability of the camera/battery-pack combination. The new L-Plates with strap-fix hex socket head screws are incredible stable. This is a great improvement and the new L-Plates also come with pre-installed hex-socket screws drivers (Figure below).