I have used hail teams and faced many hail teams and found it to be a very effective strategy overall. Both offensive and defensive hail teams have a lot of potential and it is a fairly easy strategy to execute.
Snover would not necessarily be banned if Abomasnow was. Abomasnow is good for more things than just Snow Warning, it has a large movepool and a solid statistical spread. Snover has very limited offense and if the weather were to be changed, has trouble switching into anything with its low defenses. I would be interested to see if forcing hail teams to use Snover over Abomasnow would significantly decrease their effectiveness.
As for my part, I've found that there are counters to hail teams, but most of the counters are fairly highly centralized and without them beating hail teams is extremely difficult.
Snover would not necessarily be banned if Abomasnow was. Abomasnow is good for more things than just Snow Warning, it has a large movepool and a solid statistical spread. Snover has very limited offense and if the weather were to be changed, has trouble switching into anything with its low defenses. I would be interested to see if forcing hail teams to use Snover over Abomasnow would significantly decrease their effectiveness.
As for my part, I've found that there are counters to hail teams, but most of the counters are fairly highly centralized and without them beating hail teams is extremely difficult.