I'm a big fan of SOG knives, been using them since the 90's. The SOGzilla is a great tool. I use mine a lot. It takes a lot of abuse. I've been curious to try the Byrd line of knives to compare the two, but I haven't gotten around to it yet. When I first picked up my sogzilla I decided to do a mini torture test (nothing crazy like you see on youtube). Lots of wood processing, drop tests, and I even threw it at a few trees.
The good, it actually holds an edge better than I would have guessed. Feather sticks decently enough for a folder using 8cr13mov (I think?!), holds up great with the drop test (same test broke the screws holding the g10 scales on my emerson cqc15), and it stuck in trees very well when thrown without hurting the lock up. After all the abuse there's no side to side or up and down play in it like you'd expect a cheap made in china folder. The deep carry pocket clip is nice and reversible (for us lefty's).
The bad. It doesn't sit very well in the pocket. It's very thin, but tall, if that makes sense. I have the one with the split hole which is cool if you like opening your knife like an emerson, but bad if you don't like it snagging on things in your pocket.
If you can pick them up around $20 you have a great knife at a great price. If you are paying the $30+ price point there are better options out there. I recommend checking ebay for used ones, as I picked mine up for around $9 shipped last year. This is definitely a knife to get if you want to use it as a tool, and not something to post on instagram never used.