After reading all the horror stories of these fish, I was still quite enamored by them at the fish store. I now have a mixed sex group of 5 of them living in my 20 gallon long.
What I read about Malayan halfbeaks before purchase (also yea, after reading all this stuff, a normal person probably wouldn't go out and buy them anyways)..
-Very skittish and sensitive at first
-Prone to darting and breaking their beaks on the sides of the tank walls
-Can live in acidic-brackish water conditions
-Males will fight each other for space
-Newborn fry tend to be still born
-Trouble adjusting to prepared foods, best food is flightless fruit flies
-Will be aggressive towards other top dwelling species
What I have found about Malayan halfbeaks (or wrestling halfbeaks)...
-Mine adapted to their new home VERY quickly and fit in right away
-None of this crazy darting I read about
-Never seen the males fight in the space they have (there are at least 2 of them)
-Ate prepared foods like crazy right away
-Never bothered the marble hatchet fish in the tank
I LOVE these fish. Mine have the craziest personalities ever, they lunge at anything that goes into the tank. As soon as I stick my hand in they are there in a flash biting at me as best as they can. They are in a very clean tank, and I'm sure that's vital to keeping them, as they are wild caught generally. The males of the species have orange on their dorsal fin while the females do not. I am hoping they will start to breed eventually (gasp, a livebearer that isn't easy to breed!)
If you are looking for an interesting top dweller and happen to see them, I would go for it.