It has been solid. My comparison basis is the Sitka Core Lw hoodie, and I prefer SGs durability - it hasn't pilled at all, but it doesn't breathe or dry nearly as well as the LW hoodie - still dries well, just not as well. I feel better about wearing the SG as a stand-alone layer than the Sitka, as my early season involves a lot of brush busting, but I will still choose the Sitka as a later season base layer due to how fast it dries out.
In terms of fit, I prefer the SG. I wear a Large in SG and a LT in Sitka, the SG is not nearly as form-fitting, and it has more stretch.
If I didn't have either and was looking for a do-all synthetic base or stand-alone, I would buy the SG for the versatility vs the Sitka.
*edited to add fit info and fix phrasing.