Depends on the temps you are hiking at.
Recently i've been out in some less than 10 degree for the high days, not even factoring in the windchill.
In these kind of more extreme temps, some people like to use fleece. But fleece is heavy, not that warm for the weight but your back still gets sweaty a lot, and it's bulky. This is very little weight, very little bulk, solves the problem of back sweat, and is much more weight to warmth efficient.
The good thing about fleece is that it dries relatively fast and breathes very well. However, using such breathable lining/shell and using Apex, it should dry significantly faster than most other puffy type garments.
This kind of my really cheap, DIY answer to Polartec's really expensive and new "Alpha" material, which ironically it seems companies are facing it with not very breathable fabric which defeats the purpose (or so i noticed "Woubeir" mentioning).
Btw, the insulation is not that compressed. 2.5 oz Apex isn't all that thick to begin with.
Granted, hiking at 25 and above, especially if doing a lot of steep elevation gains and loss, this would not be a good garment to use.
Unfortunately, i live in VA, and most hike near SNP which has a lot of gentle hills, etc, and often i get cold going down or flat when hiking at temps less than 20/15 F.
I could bring my heavier fleeces, or i could bring this 2.3 oz garment that takes up no space in my pack…