The Cor-Bon 135's are excellent, and I sometimes carry them. However, they do have a (quite deliberate) design limitation. Because of their very high velocity (for caliber), they expand brutally fast, and due to this and their light weight (reducing momentum) they slow down quite fast. They typically don't penetrate as deeply in flesh or gelatin as the heavier rounds.
This can be a problem if the BG is wearing heavy winter clothing, and/or is a very heavy-set type, as the bullet may not reach vital organs. It can also hinder penetration through windshields, cover, etc. On the other hand, it's a perfect approach for the "average" civilian shooter who wants to avoid over-penetration at all costs, and is much less likely than LEO's to have to shoot through cover, windshields, etc.
I carry the Cor-Bon 135gr. when I'm planning to visit a shopping mall, or somewhere where I'm likely to encounter large numbers of bystanders. I obviously don't want the moral and legal hassle of injuring an innocent person through over-penetration if I have to use my weapon in self-defence! On the other hand, my standard "general-purpose" load is the Remington Golden Saber 165gr. JHP. It has much superior penetration for heavy clothing/body fat/muscle mass/cover/etc., and still expands very effectively and has a very good "street" stopping record. Sometimes, if I'm going to move between general and crowded situations, I carry two spare mags, one of the Cor-Bon and one with the GS. Before I go into a mall, I'll switch carry ammo. When I come out, I'll switch back.
Works for me... YMMV.