I've had really good success with them. I have one of the cordless drivers, impacts, multi-tool, sawz-all, circular saw, vacuum (LOVE IT), orbital palm sanders, LED stick light, job site light, and angle grinder. I got most of them from Lowes when they had a deal where if you bought the bare tool they'd throw in a 6Ah battery. Sometimes the tool would be like $90 and the free batteries were like $150... Just couldn't pass them up! Even got my dad a couple of bare tools just to take advantage of the free batteries. He already had the older 18v Dewalt tools so he was familiar with them. Also got him an adapter to use the 20v batteries with the 18v tools. He's been happy as well.
The 1Ah batteries are okay for the driver and impact if you're not using the driver constantly. Otherwise they don't last too long, but they charge really fast, like 30-45 minutes. Oh, I also have one of the string trimmers (dual string) that does a great job. That came with a 4Ah battery which I actually use on the vacuum. Believe it or not, for as much as I use the tools, that portable vacuum was absolutely the best purchase. It gets used multiple times per day. Just wish it had a bit more suction. But it has a synthetic filter so I can go from dry to wet without having to remove it. That's come in handy a few times.
In all I have like 2 or 3 1Ah batteries, the 4Ah, and three 6Ah batteries. Since the first purchase, which was xmas 2019, the 1Ah batteries are as strong as ever.
I have some Ryobi 18v tools and their smaller 1Ah batteries suck. I like the tools, but the batteries have a lifespan of like a year before they won't take a charge anymore... and they're the Lithium Ion, so the newer tech. Disappointed in those.