The Space Grips can be OK, but they'll only take so much weight. The Swing Grip variant seems to get the most flac, and the Topeak Bar-X-tender seems to be one of the more solid of the type. I've had the Bar-X-tender loose it though, when a bit too overloaded with a couple of heavyish lights (An Exposure Race Maxx and an Exposure Joystick).
The SJS one you linked to looks like it's probably reasonably solid, so long as you want things mounted above and below, rather than side by side.
The Space Grips can be OK, but they'll only take so much weight. The Swing Grip variant seems to get the most flac, and the Topeak Bar-X-tender seems to be one of the more solid of the type. I've had the Bar-X-tender loose it though, when a bit too overloaded with a couple of heavyish lights (An Exposure Race Maxx and an Exposure Joystick).
The SJS one you linked to looks like it's probably reasonably solid, so long as you want things mounted above and below, rather than side by side.