I'm not a fan of Elgato's other products, but the Multi Mount system is an exception. The individual parts feel good, and the mount is mostly rigid when locked in place. The Solid Arm is indeed solid, the pole mount pads have a cut-out which makes for better grip, it's easy to adjust with the handle in the same style as the Multi Mount's desk clamp, and the end has a ball joint allowing you to position the equipment you've screwed onto the end at any angle within a hemisphere. The only issue I have is that it doesn't include a cable clip, and I feel that as a 'premium' add-on, it should.
Recommended when using with the Multi Mount (I haven't tried mounting the Solid Arm elsewhere yet).