Using Perish Song to stop Moody is not very reliable if the opponent has a Wobbuffet. Unless the user is Ghost Arceus (Dark is rare, Bug?lol) which is using Perish Song, the rest of the Arceus forms will get trapped and you die while the Moody user can switch out.
I played a bit on the ladder, and most of the time you don't see much Moody users, I was one of those who tried Bibarel and Glalie and even shared some teams with a few. I already reached high enough to qualify for the vote by using the Moody team but I will not identify myself.
What I think about Moody is once that Beaver or Glalie gets a free switch in, or just get lucky, chances are you are going to hate facing it. Even if you have Calm Mind Kyogre or Latias with Thunder, they might just get lucky and obtained Speed boosts. Thunder's 16 PP can be stalled out with Protect + Sub, which even if it fails will stall you out for tens of turns.
Don't think Bibarel and Glalie have such shit stats they are useless. At +2, Bibarel's Return is an easy 2HKO on Kyogre and Waterfall still packs quite a punch in rain. Glalie has both Taunt and Frost Breath which crits 100% of the time so don't think you can CM alongside it and win in the end, just not happening. Although Frost Breath has only 16 PP so that can be stalled out if you have Blissey + defensive Kyogre or Ho-Oh but if just Stealth Rock is down, then you can't win. Oh, mr.Beaver gets Taunt too so watchout! You can argue Giratina walls it but you can't do much back to Beaver, so it only delays the Moody roll. Glalie hates defensive Kyogre with Roar or Thunder but as mentioned earlier, those evasion boosts will annoy you a lot. You can't stop them with walls all the time and they sometimes carry Taunt. Also, those Roar and Whirlwind might miss lol.
For Smeargle, it abuses Moody the best. It can just spam Protect and pass the boosts safely although it takes sometime compared to Shell Smash, no one is stopping you from using Moody and Shell Smash together! White Herb can still save all the stat drops if your recipient has it. +2 Evasion combined with Shell Smash passed to your sweeper? It will be almost game over. If you are fan of long stalling, Smeargle can find an opening and sweep with Stored Power as long as you get a free switch in and you can even come in on Ghost Arceus if you are feeling lucky, because Arceus only has 8 chances to Focus Blast you. If you grab a Speed boost, you already won the war with Ghost Arceus by spamming Protect and Sub. When you gathered enough boosts, sweep with Stored Power, and even with Smeargle's bad stats, Stored Power is killing things with a lot of boosts. Bibarel can do the same because it is immune to Judgment and Shadow Sneak which is pretty fun.
The only flaw of Moody is you need luck to succeed and if you don't get the boost you need, you die. Also, most people posted their experience and I have to agree with shrang. You get angry when they don't give you the boost you want, but your opponent is annoying you with that lucky Speed boost, and that happened a lot. Luck > Skill, it can turn the tables on you and don't be surprise if Bibarel 6-0es your team, it can easily happen if you give it a free Sub.
master ubers
This is my post with the reqs