I don't use fleece anymore. Period. Well, except for cold weather carpentry or gardening. or for thrasher rock climbing. So I can't corrolate w/ various weights, anymore---I forgot. I go for the lesser weight and better compressibility of a polarguard jacket/sweater.
Generally speaking, I use my Cocoon or Micropuff, 1st thing in the morning or at eve. in camp. When I'm moving, a baselayer and a shell will be more than enough.
I consider myself a fairly warm blooded(cosmopolitan--pardon me, perhaps an obscure joke). At 40 degrees, stationary for rest stops, my baselayer and a shell are quite enough, if I use a warm cap/balaclava and use something like possum wool gloves. I just don't need to break out the Cocoon let alone a fleece garment. At 40 for long term stops or at temps, below 40 is when I break out the insulated jacket.
When I need to go light ( but not climbing and hardcore backcountry skiing applications), I use either the Micropuff or my Cocoon. I tend to adjust base layers to perceived need. So I will use a short or long sleeved LW merino wool baselayer, or when conditions will be a bit colder, a med. weight baselayer. Baselayer+Insulated jacket+shell options keeps me very comfortable for all my Summer Cascade,Trinity,Sierra, Wallowa backpacks.
For those other applications, I go softshell--either an Ibex Icefall or for cooler conditions, a Beyond Fleece Cold Fusion. This is supplemented by an old Western Mtneering Down Parka,when bloody cold.This takes me through anything short of high altitude winter mtneering.
No question that the micropuff is a little more rugged than the Cocoon---you have to baby a Cocoon a bit just like a lot of SUL gear.
Like your website , Mark---probably the best single source for considering various gear on the web in an easily accessible format.
i wrote my response in a very distracted way, earlier. Hopefully it now makes sense.