I'd say theyre pretty similar quality. And don't worry about exploding lipos, thats basically a myth, it only happens to idiots in youtube videos that stab them with screw drivers or hook them directly to car batteries or whatever. I treat my batteries like sh*t and the worst thats ever happened is the casing gets a little baggy and they loose their power and capacity, and that was after some shocking punishment.
edit: may as well add, if you are seriously worried about explosions, those cells probably won't be any different to polyquest or whatever - all you have to do is adhere to proper charging rules etc and they are all as safe as each other.
I haven't tried either brand cells, but cheap lipos like that are usually all similar quality chinese cells - most probably underrated in terms of current draw ability as well (though some people on the hc forums have posted decent looking graphs of the zippy lipos).
are those cells worth a crap? are the swangs worth a crap? i dont want no exploding lipos on my hands...
I have 2 of the Zippy H 3S 20C 5000mah lipos. They are very good. I have over 70 cycles on them with zero problems. Just check the dimensions to make sure they fit your application.