Tying it is a snap and I've done so many times while lifting 100-300lbs. For example, for testing I've rigged myself in a mountaineering harness and tied it as I'm hanging in mid air (I weigh about 230lbs). Note, I'm lifting that with a rope pully system so there is a mechanical advantage that greatly reduces the weight "I" have to either lift up or pull down.
To tie it, I run the working end alongside the group of other ropes running parallel that have gathered together as a "bundle" as I rigged the pully system. Then, I grip all the ropes including the working end in my left hand (I am right handed) using the thumb, middle, ring and pinky fingers. You can actually hold a lot of weight in your hand like like that. The index finger is free and the working end exiting the top of my left hand is relatively loose. I pass the working end over the top of the index finger to pin it for wrapping up the ropes. Then I wrap a few times up the rope with my right hand, pull the working end down and across those wraps and finish the hitches.
I'm trying to visualize how I do the turn through the ropes right before the last half hitch. It's easy for me to do in practice, but it's a bit much to describe with text. But, it's a one second move and I suspect if you tried it you'd work it out easily if you've followed along so far. It involves shifting my grip with the left hand so none of the fingers are grasping the line that leads into the wraps, and then creating a bit of clockwise force to open the gap between the the main group of ropes and the part of the working end that has been added to the bundle below the wraps. I then place the working end in the left hand to hold it as part of the bundle so I can let go with my right hand and reach around the back to grab it again. After that, the final hitch is easy. In general, I dress the hitch after the second to last hitch and then dress it a bit more after the last one. Relatively speaking, dressing it is easy especially after the second to last hitch because the last half hitch provides a lever for the whole system.
The problem with the Sailor's (Gripping) hitch is that under tension it is very hard to perform the final tuck under the ropes. With the variation that I show the final hitch is a snap.
I can probably tie the whole thing with 200lbs with a slipped variation and three turns in under five second. Unslipped and that depends on how long the rope is since I'd be pulling it through the final half hitch. With 8mm hemp, using only one turn and supporting my own weight, bouncing up and down in the climbing harness does not cause the hitch to slip. Using MFP, three wraps consistently accomplished the same result.
(Edited to better explain method of tying)