This topic concerns specifically two ZT knives, The 700 and 630SKD. A denizen requested for me to comment on these knives so I figured I would make it into a post instead of a lengthy missive sent through email.
There are some pretty huge difference, but overall their pretty similar simply because they carry the same ZT trademark manufacturing processes.
The 630SKD claims to be 30% lighter, which to me means one thing, they’ve lightened the blade. With that said, it’s still heavier than the 0700. Obviously some people find the ZT3X knives too chunky, too heavy for EDC or pocket carry. This is totally an option for people who want to dip into both worlds. Unfortunately the chunky blade is one of ZT’s hallmarks. You’d have to ask yourself what’s the point if your not getting everything ZT is known for.
With out getting calipers out and doing a direct comparison it’s hard to talk with a lot of certainty about the blade differences. Both are made out of the same steel however. As an owner of the 0700 I can speak to it’s ability to penetrate objects. The two distinctive cutting surfaces bake cutting fairly easy. On the 0630 blade it appears a lot of cutting would be done on the forward belly.
The handle on the 0700 appears to be more aggressive. I don’t doubt the 0630 is fine, but the 0700 seems to be built more towards a fighting grip than perhaps the 0630.
If you are in the military, the carbide glass cutter may not really interest you as combat vehicles don’t use a lot of automotive glass.
The speedsafe is a great assist design. A lot of people praise it. I’m one of the followers of the esoteric cult of manual knives. I do own and have used autos and assisted knives before. For something that is designed to be carried a LOT, I feel like it should be a manual. Not being able to control the speed of the blade just plain sucks and limits the deploy-ability of the knife.
Certain people might advocate that the speedsafe ensures proper lock up. This is a facile argument. If your liners or framelock is properly built it shouldn’t matter how hard or how much spring power is behind the deployment of the knife. The 0700 has great lock up no matter how fast or hard I open it. The speedsafe design is irrelevant in this situation.