I can relate, having used Cloyster for fun before. Since we've both failed to get decent streaks with it, we can probably conclude that it sucks in the Subway. Rock Blast's accuracy (and that crappy Water move I don't even want to name) ruins many sweeps. Yeah, the team context is arguably the most important factor when it comes to choosing a dragon. I have enough experience with Salamence in 4th gen, it was central to my 646-streak team as posted here: http://www.smogon.com/forums/showpost.php?p=2493741&postcount=2138 ... so I can completely understand all the advantages such as switching back and forth with Registeel to get Intimidates. As for its bulk, it was only just enough for its Substitutes to survive certain Tricked attacks such as Heatran's Magma Storm through Light Screen, but in the Subway the general power level of Pokemon has increased, so I'm sure there are more things that can break a Salamence Sub. I was mainly using it for fun (such as getting up to 49 quicker than with my main team) and experimentation, so I didn't have a team perfectly designed around it. I also used Adamant. I've been using methods other than Trick to set it up, though... I completely forgot Dragonite since I've never used it in the Tower/Subway... I also have no Dream World access, and can't get Multiscale. What are these 'really bad matchups' you speak of?