I had tried simply using a single case gauge as well as a 7-case gauge, but the tolerances on those were either too tight or too tedious to use. For just twice the cost of what I paid for both the single and 7-case gauges, I got this one and am so glad I did so!
This takes roughly 2-4 minutes to fill with 100 cartridges, but definitely worth the time. I have noticed a couple of the slots are slightly different, to where if a cartridge sticks up on one I have to drop it in another hole where it will fit fine, but this only happens maybe once out of 200-300 that I check. I wouldn't be surprised if it was just inconsistencies with my mixed-headstamp brass, though.. Other than that, this thing is great and has cut down my gauging time to less than half!
Also, after you've got 100 good cartridges, you can flip them over into an MTM box just fine. You'll have to wiggle them a little bit to get them to sit just right, but I haven't had any fall out doing that unless I was trying to rush.