I'm not asking you the questions to defend Synthis CPU usage or something like that, and i don't say Synthi V does'nt use much CPU, like you seem to think, that i do. Buchla V also use much CPU.
Some of Arturias synths can use much CPU, especially when used in poly modes. So can other vendors applications for that matter.
I too hope, something can and will be done about this.
The developement seems to be that plugins use more CPU, as the CPUs become better. Some can be explained with better quality and such, but i also think, that developement might not take enough time to optimize the performance the way it was needed before . But i can't tell for sure. I actually think that more optimization is needed even today, if it's technically possible.
Even new strong CPU's can have a hard time with some sounds in some applications from different manufactors. So it's hard to run many plugins, because they have a high CPU usage.
But i also wan't plugins that does'nt sound the same as allways, and emulations that actually sound like the originals, and that may require more CPU usage. Andi even think emulations still could be better.
Just in case: The Lost Beacon Pad you mentioned in your first post has a overdriven Envelope output Signal that cause distortion. If you don't wan't this, then you can turn the Envelope Signal parameter down a little.
If you hear distortion things like this can be the reason.
I must say, that you compare things, in a way that's not helpful to understand and compare the CPU usage you have, as you does'nt tell anything about your CPU or your soundcard and computer settings. So it's not possible to see, if there is more to your troubles, that Synthis CPU usage.
I use a Ivy Bridge "third generation" i7 CPU and i can run Synthi V including the preset you mention. And i can max out a CPU core with other manufactors synths. But that does'nt tell much about actual performance without having technical and more precise data though.
But yes i agree that some synths use too much CPU, if it's actually possible to optimize them to use less without loosing quality, If that's the only thing you wan't from this thread.
If a plugins CPU usage is to high, then many will choose or have to not to use the plugin.