I have both the Sirui L-10 and the Wimberly MH- 100 (actually the Leophoto version which is a direct copy for less money, the MPG-01). I am off to the Pantanal where it is possible to use a monopod from the boats and have been sitting on my porch switching between the two to decide which to take with my RF 100-300 f/2.8 (heavy sucker.)
With the weight centered (Sirui) the rig tends to easily lean left and right and can be tough to keep a vertical balance. The Leophoto seems to be better with the heavy lens, as with the lens on the right, I can hold the knob of the gimbal with my left hand, and since the weight is on the right (so pulling to the right only) it seems easier to keep vertical. With the Sirui, that heavy lens, has much worse balance issues for me.
YMMV.
ps: my shooting buddy has the Wimberly MH-100 and we shoot side by side a lot, and the Leophoto version is truly identical to the Wimberly except for the knob color, and it cost $40 or so less.