Actually, I only meant the calc was relevant for the set he posted :p And I will be honest and say that I didnt even think about Probopass's speed at the time. And I love Probopass..
And, looking at your calc the damage is pretty much the same, but the difference is Gothitelle is running a lot less Bulk with Cacturne having only a little more attack. This is a little off topic, but I think that means the calculator I use may have been wrong ;-;?
Edit: Needed to actually add to the discussion without an almost useless post. I've seen a lot of people carelessly getting boosts with Gothitelle, and not switching when something threatens them. I'm not accusing you all of this, but, it's happening. I had my Sub+Salac berry Samurott in, and after it got a kill they switched in Gothitelle. Surf easily did 50% (actually, that was prolly close to max), spikes did 12%, and rocks did 12%, and they decided to Calm Mind. Don't be careless with Gothitelle; know when you can set-up. This could have went without being said.
Also, I've battled some people with Rest > Substitute. I thought this was pretty interesting; coming in on something that can't threaten you in the slightest, especially under screens (Screens weren't up at this time), then boosting until you can rest. Then, as you sustain small damage, just retaliate.
I only find that useful for the recovery aspect. Otherwise, sub it generally better for blocking Priority in a way, and blocking status without possibly wasting some turns in which your opponent has the chance of getting a critical hit while you sleep. Sub also allows you to be ready for the next Pokemon to come in.