I think the logo itself is fine, if a bit, as a previous poster said, cartoonish.
The problem I have with ZT (and they are not alone) is that they slap the thing, about twice as large as it needs to be - and it isn't subtle or sophisticated or cute or anything remotely redeeming - prominently on the show side of the blade and bugger the aesthetics of a perfectly good looking knife. Case in point the soon-to-be-released 0460. Really, ZT, what are you thinking????
Yeah, CRKT does the same thing: I've got a perfectly good Drifter (great little knife, BTW) and it just ticks me off every time I look at it 'cause it's got this HUUUUGE (comparatively) "CRKT" plastered all over the blade, and an equally obnoxious DRIFTER adorning the pile side. Dude, I know what it is, OK, I bought it. And no one else cares. And if they do, they will ask me. And the dang things are slightly tilted, I am sure, which just ticks me off further.
I digress.
I'll give ZT credit, though: on the 0450s they put a more subdued logo on the scale, though it should have just been a simple ZT in a teensie-weensie box, and not the whole name spelled out - heck they might as well have put in "A Division of KAI, Inc., blah, blah, blah..." as well - and it would have been better. Oh, but they couldn't quit when they were ahead, though, and they went and put the dang logo on the clip! Yup, had to have it on there, somewhere. C'mon, do we really need the logo on the pocket clip? We know what knives we are carrying. Do you really think...and I mean YOU marketing department, that some guy is going to try to read the logo on the pocket clip of some other guy's knife while it's in his pocket, and that this is going to increase your brand exposure??? Crikey, I wear bifocals. You think that's going to end well? "Yah, don't mind me bro...I'm just leaning down by your junk here to read that logo on your pocket clip...."
No. You. Don't. It just looks fugly.
OK, too much coffee. Rant closed.
I do like the Spyderco logo. Love that little spider, actually. Just so long as it doesn't grow to Bird Eating Spider size and take over most of the blade real estate. Oh, and the DPX skull guy is pretty cool, but I think they just put that on their packaging. Would look pretty stupid on the blade, IMHO.