I have a ZT 0450 and like it fine...but the handle feels a little too slim in my hand, and i have average sized hands
Not a fan of the Domino; it's only a so-so flipper and the pocket profile is huge. It's a very heavy, chubby feeling knife with a ridiculously short cutting edge.
I love my Gemini, but as others have said, it's not readily available at this time. There are also some QC concerns that seem to be simmering regarding some of the most recent Kizer knives. I know I'm kind of waiting and watching before adding more Kizers to my collection. Kizer's growth has been the fastest I think I've ever seen from a knife company, so we may be seeing some evidence of growing pains.
Love my LionSteel G10TRE and Southern Grind Spider Monkey...the Spider Monkey in particular is an incredible blade!
Consider perhaps looking at the ZT 0808. It's only a little bigger than the 0450 but seems to fit in my hand a lot easier. It flips a little better too. The grip on the 0450 is so thin, many people have a hard time gripping and flipping without depressing the lock bar. YMMV.
If you're looking for a Shiro-type-look without the Shiro-type-price, check out the RealSteel Sea Eagle. The Diskin designed Kershaw Strobe is an awesome knife of similar style also.
Also, consider purchasing either the 0450 or 0808 from USAMadeBlade. Awesome service and some wonderful custom anodize jobs for no additional cost. They've got some sweet 0450's and 0808's available right now.
http://usamadeblade.com/Anodized-Knives_c65.htm
(No, I don't work for them or get kickbacks

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Good luck and enjoy your purchase! Check back to let us know what you decided.