Lot of short-lived DC books in that period.
I was there during the Implosion of '78. It wasn't pretty.
Some stuff I liked at the time: Freedom Fighters, SSOSV, Plastic Man, etc - probably because they were some of the few books that actually got shipped over here on a regular basis.
I still preferred Marvel though.
I had gotten into DC first as there were far more of their titles coming over (at least to London) in the early ' 70s. By the mid to late ' 70s, I was reading more Marvels than DCs. The three titles you mentioned were amongst the best that DC were putting out at that point.