For what it's worth, I'll reiterate: these are nice fish. You haven't been sold a dud. They do fine at tropical temps up to about 25 C, because they will breathe air if they need to. In groups, they become very tame.
As Fella said, they're playful fish. They're among the very few fish that actually like being touched, or at least don't mind it, and will swim up to your hand and easily become hand-feedable. On the other hand, don't keep them with anything aggressive. They're far too gentle for that.
The usual species is Misgurnus anguillicaudatus. The Japanese word for loach is "dojo", hence "dojo loach" simply means "loach loach" (sort of like how "koi carp" means "carp carp" or "the hoi polloi" means "the the people"). Weather loach is more common in England, and refers to their use in historical times as natural barometers. They respond to changes in air pressure by becoming more active, typically swimming up and down a lot. People apparently used this to predict changes in weather.
They get to about 15 cm or so, are harmless to even tiny fish, except perhaps livebearer fry, and will eat practically anything. Bloodworms and other small inverts are a favourite though. Keep the tank covered: they can jump well! They love to dig, but generally don't damage plants in the process (at least not once the plant is properly rooted).
If anything, these are much better aquarium fish than spiny eels. Perhaps not more interesting for a collector, but in terms of sheer fun and easy of keeping, these are among the most robust and entertaining aquarium fish out there.
Cheers,
Neale