Lol, I noticed you have a "hitchhikers" thumb Nebula. I have one too. It's genetic but neither of my kids have it. Neither does my brother or parents. I guess I'm a freak...
I really do love the simplicity and cost effectiveness of this diy.
The lids in those tubs seem a little flimsy. When the plant is full grown does the lid keep the plant in its place? I'd be concerned that the lid may bend and pop off the tub.
I never knew what a hitchhiker's thumb was until just now! I had to look it up

(For those who don't know, apparently it's when your thumb can bend back a lot)
The lids are flimsy, but strong enough to support a plant throughout its life. Even if the plant completely tips over and the net pot starts leaning, the lid will stay on just fine and the net pot won't pop out even with a very large plant covered in heavy bud (learned this from experience). I've also found that if you align your plant so the manifold is diagonal against the center, that it will almost never tip.
Example of a plant tipping completely. One day the plant was tipped like this but since it seemed completely sturdy at this point I just left it alone until harvest. The depth of the net pot compared to the diameter of the hole keeps it from tipping more than this in normal situations. I did have to string up the buds with
plant yo-yos a little bit by the end of the flowering stage, though. You might be able to see the almost invisible string and yellow pieces in this pic. However, that was mostly because the buds were falling down away from the center, not that the actual plant was falling down.
Here's an example of making the manifold diagonal (which I've realized helps prevents tipping)
Grown out with the diagonal manifold - no tipping at all even though the plant was almost half a foot taller
Here's another example with plants that each got over 10oz of bud. They weren't even on a diagonal!
Even with the diagonal method, I would never reuse a cheap tub like this though. Why not start with a perfectly sterile and new reservoir every time? I always toss all my tubing between grows, too, since it's incredibly cheap yet difficult to clean the insides.
These 10-gallon tubs only cost $7 from Wal-Mart so they're basically disposable. I have a
3-5/8†Hole Saw (power drill attachment) which lets me drill perfect new holes for net pots in a few seconds. That ends up working out perfectly for my purposes
