Ball lightning is OP if you want to do all content go for it. Can solo uber lilith on lvl 80.
If you play casually though, and not gonna play to the max, ice shards are fine and maybe even more satisfying, just stack some lucky hit, max snap freeze, avalanche, get aspect of frozen memories and with iceheart brais you will just shatter the whole screen and won't have any mana problems. Can get lvl 100 and push till tier 50-60 nm dungeons pretty easy.