I should have recognized your name before, sorry. I remember this model from our previous thread. Is it lagging when in 4 up view or also in 1 up view? 6,700 kb doesn't seem like that much to me, so it's a little surprising. I wonder if you pin the morpher to the modifier stack and unselect the model if it also lags. (Like, is this related to selection + morpher or just morpher?)
The problem from my limited understanding is that since the morpher is using every vert as part of the definition, it's got a copy of the model x the number of morphers. So the poly count goes pretty high under the hood for deforming, even when not in use. Hopefully someone with more knowledge about it will post in this thread. Even then though, it shouldn't lag is so much unless maybe it's single threaded, I'm guessing.
Maybe this article has something that might help, but I have my doubts. I googled for a while to try to find any threads about lagging morpher and I couldn't find any, so it may simply come down to something specific with your setup, or the poly count is just in the upper levels for the Morpher. When the morpher was originally made, 65k verts on a model was considered crazy high. It's no excuse, just an observation. As a workaround if the only morph is the throat, perhaps setup a single loop of it while it's lagging, then turn off the morpher and duplicate keys as needed. That's not a great workflow, I know. I apologize in that I have little suggestions here. I truly hope someone else does.
You might try turning off the viewcube or using a different display driver in 3dsmax. Beyond that, it's kind of a lot of polys for a typical morpher, at least from what I've seen in my travels. Or, perhaps it may be necessary to make a low poly version of the model that has maps baked from something high poly like this to handle displacement to get it back into this shape. That's not what you want to hear though, and I admire your ability to skin something this dense in the first place. Hats off to you. If you do go that route, you can transfer the skin from your 88k model to the new one in seconds with skin wrap, so it's not a total loss. That's my best suggestion if all else fails.
Best Regards,
