I use RRS L-brackets. The quality is exceptional, worth the price. However, they do not switch between models of cameras like a "universal" L-bracket would. This is a factor to consider.

As another person said, they are configured to fit your particular camera, not only for the openings, but also for fit against the camera body. This prevents rotation. Their camera plates are the same type of design. This is also a factor to consider. The "universal" L-brackets and camera plates are flat, so when using a heavy lens on a tripod, there is more risk of rotation [unscrewing from the body].

I also agree with the suggestion to look for pre-owned if you want to save money. You may not find the right one right away, but it is up to you whether you are willing to keep searching or buy new.

I have 2 cameras, each with its own L-bracket, that stays on that camera all the time. I also credit the L-bracket with helping to prevent damage to my camera when I took a fall, with it on a strap around my neck. [Also the lens hood helped.] The camera got a bit muddy, the L-bracket got a ding, but camera and lens survived with no damage! There was undoubtedly a bit of luck too, but luck always prefers a little help!

Hope this helps with your decision.