Thank you all for your input.
Well, I think...not 100% sure, but I THINK for this purchase I am going to get the ZT 450. Deciding between the 'natural' titanium, and blue anodized versions, red standoffs be damned. One of the deciding factors is that I feel it will best replace my BM 940 in the size, weight, style capacities.
However, doing all this research I discovered:
The good news: I am now no longer desiring the TRE G10 flipper. Among other things, I hate the G10 backspacer. And on a 'gent's folder' which is really what this is, the G10 looks out of place. It makes the knife look cheap, which it certainly is not. C'mon, all that beautiful work on the titanium scale and lockbar, that great M390 blade, and you put ho-hum G10 on it? Really? They could have gone with polished G10, as on the Enzo Birk...that would have looked much better, and an aluminum backspacer, anodized green, red, or gray. And still come in at a price point significantly below the TRE.
The bad news: I MUST have the 'real' TRE. Just can't decide between full TI with blue or bronze clip and spacer, or CF. Man, I love the looks of that knife. No, I don't NEED the 3 opening methods, but it is cool. And, hey, I might like the thumbdisk better than the flipper, who knows? And since I'll already have the 0450 flipper...
I also discovered that I will not sleep well until I at least try - not sure I will keep- an SR2-A. Yeah, I know it's not a flipper, but I got distracted and what can I say? It's a good looking knife. And should be very pocket friendly. I'd like the violet SR2 in TI (yes, I am quite secure enough to carry a purple knife), but I am not willing to pay the premium for the color, and the extra weight. (Talk to me again at the end of the year and see how business was, maybe I will change my mind if I've moved on the SR2-A.) Hey LionSTEEL, you need to make a navy blue or sky blue SR2-A! Have to decide between red and orange.
More bad news, from a fiscal standpoint: I am seriously considering pre-ordering the ZT 0460 flipper. Yeah, kinda similar to the 0450. My rationalization is I don't have to keep both, I could flip one. Not sure that will work if I like them both though, and at it's expected retail, the 0460 doesn't qualify as an impulse buy. But, damn...that is a good looking knife. I'm going to have to think about this.
I still want a ZT0900. It's actually kinda ugly. But it feels great, flips great, and I just really like that stubby little thing.