As many replays as I've watched I'm pretty sure I've got a grasp on what Master's level play looks like.
That's super subjective, because I've likely watched as many games or even more of higher level games, including GMs and I can say that Sidewinder's is a top level game at minimum High Masters level. Definitely not mid or lower. This statement of yours is as meaningful as mine.
Also, RuneK, I don't think you should be criticizing the level of play in this replay, and should be focusing on the actual play. If you do not agree that MS is the answer, then state your reasons, and if Sidewinder says he already considered those factors and still thinks this is the solution, and gives his reasoning, then you should defer to that reasoning and maybe try it out yourself, or allow time to tell whether this is correct or not from a follow-up game from Sidewinder.
I don't think you should be attacking him the way you did. I can agree that Sidewinder did have some snarkiness in his reply, but I don't think it was unprovoked...
To keep this thread positive and FOCUSED on strategy, let's just move on and talk about the actual strategy:
Based on the play that Sidewinder used vs the Zerg, it is a typical lategame skytoss/Templar look, and the response is what GM Zergs and pros like Rekatan and Catz have been advocating as the answer and it seems to be quite effective too. Mistakes were made, on both sides, but those notwithstanding since we are talking broad lategame startegy since the mistakes did not really affect the interaction of Sidewinder's composition choice at its strongest with the Zerg's choice, there is a possibility that Mothership is the correct answer since MS Core became less and less of a determining factor as Photon Overcharge is just another photon cannon's dps, but costing energy instead of resources per se.
Mass cloak seems to be a way to keep High Templar alive and counter Locusts better, and provide HTs with longer effective range to land feedbacks and storms on Viper/Hydra/infestor and allows the rest of the army to kill locusts without taking damage, especially with Tempests being able to snipe Overseers in 1-2 shots.
We have a couple of replays from Cazdog as well to demonstrate a trial when using Mothership in late lategame.
So, RuneK, I highly recommend you try this to find out for yourself why this choice is strong or weak. Because at the moment, you aren't talking from experience and your counter to the logic of the strategy is not sound.
PS: This is not me trying to be insulting or demeaning, and I apologize if it came across as so, but I think that it is not constructive to get into these kinds of fights, and I'd rather we focus and concentrate on strategy talks.
Right now, Mothership looks like the best solution, considering the effects of mass cloaking and the STILL existing possibility to use Mass Recall and Time Warp, just the same, and a stronger attack than Photon Overcharge = Mothership attack dealing 36 damage per shot > 20 damage per shot, at the same dps, which is ok, since the attack is free and does not cost energy. The main advantage we are looking for here is the mass cloaking.
I await your reasoning as to why this is not a reasonable response to a turtling Zerg with Swarm Host/Viper/Infestor/Hydra with mass static defense.