V3, V4, IP Trickler, SuperTrickler, it doesn't matter. There is NO powder thrower/trickler system on the market that WON'T throw a wild charge once in a while if speed is your goal, it's the nature of powder kernels. However every system I mentioned IS capable of nearly perfect throws if you sacrifice speed.
To the OP's questions, the V4 is 100% worth it if you work between a lot of different powders and charge weights because of how it works. If you only do a couple cartridges and don't plan on expand on that, maybe stick with the v3.
On the notion of a kernel lost here or there, here's a great example of how to view this idea that SuperTrickler has in their owners manual.
"The trade-off between speed and failures.
Powder and granules are notoriously difficult to dispense. Given enough time, you can slowly trickle the powder for an accurate charge every time. However, is this the best approach?
The trade-off: You can go fast and have a few failures every now and then or go slow and rarely have a failed charge. We are all different, so the choice is yours. You may prefer to charge fast and discard overcharges, or you may prefer to charge slower and rarely discard overcharges.
Do not expect 100% successful charges, unless you want to trade dispensing speed for time.
If you were to do 100 charges at no failures, but each charge was 20 seconds, the total time would be 33 minutes and 20 seconds.
Now let’s look at the same scenario if each charge took only 6 seconds, but with a 1 in 10 failure rate. The total time would be 11 minutes, a saving of 22 minutes and 20 seconds.
Even if the charge time was 10 seconds, with a 1 in 10 failure rate, the total time would still only be 18 minutes and 20 seconds. This is a 15 minute saving in time for the sake of a few rejected overshoots. Do not be concerned with a few overshoots if you can save considerable time, but the decision is yours."