Metal boxes are not like bags, they're easy to slide on carpet and maintain the same outside shape and size. This minimizes storage hassle and dead space.
Did you replace them because of the purported weight savings? If so; congratulations, you gained .002 additional MPG from switching from metal boxes to plastic containers.
Most HFTs are decent for the price. However for a lot of the under $10 items can be had for a few dollars more with much better quality elsewhere. HFT is best for consumables and things with no moving parts.
Yeah; I'd rather carrying a jack, jack stands, 4 way lug wrench, an intermediate tool set, intermediate amount of replacement/spare parts and fluids, 2 gallons of spare gas than be stuck without them. The cost of calling a tow truck 1 mile from the paved road to change a tire because one left behind their jack and jack stands to save fuel, wipes all any and all fuel savings. It's another thing entirely if one didn't have the m-o-n-e-y for the required tools beforehand, I feel sorry for you for being too poor to be proactive.
Some people with macgiver mindsets will say "use the tools around you" and "it's an adventure", and not carry more than a couple swiss army knives with them. They are the ones that call for help after drinking their last ounce of water, and have spent 4 days trying to fix a tire with branches, rocks and their mind. I rather have the tools and not need them than to need the tools and not have them.