All the talk about how being as fast as the Kea is good enough because it was fast enough when it was made is kind of assuming no one else is progressing their own technology. I sort of fell into this trap with the shield vote earlier assuming light would be fine. Our neighbours aren't standing still, so building something that would've been good enough 30 years ago isn't really a reliable investment.
Understandable but you're rather missing the point. If we take the minus .6 option, have the worst possible nacelle configuration for it sans perhaps single Nacelle, and don't prototype the new nacelle we know Yoyodyne is working on we're at the Kea's top speed. I understand the Kea was 30 years ago. But the D6 is still a standard Klingon design and is left in the dust by the Kea, and the D7 gets dumpstered by the Excalibur. I'm not saying it'll beat a D7 in a race alone but it'll at minimum with the least favorable metrics at least make it work for it and cleanly outrun the more common D6. And that's a conservative estimate if we deliberately choose options to make this thing slower. If we take cruise configuration nacelles we make an even warp 8 or 8.2 which blows the Kea out of the water, easily
Furthermore, this is not a warship. Starfleet Tactical is MORE than happy with their Swords and Sayle is on record of saying this design isn't going to be relevant in the four year war.
What is relevant is going to be cost. How much this thing costs, and if go full ham on all the bits and bobs here and now like the thread has a habit of doing, we'll end up shooting ourselves in the foot for it's intended purpose.
Don't get it wrong, i am 100% against taking both options. That's a terrible idea. But one still leaves us as fast if not faster at warp than the Klingons who out tech most anyone else we'll see in the near and midterm, make us highly mobile at impulse which means we're a lot harder to kill if a fight does break out, and reduces the costliness of our shield and raises how efficient it is.
Please don't mistake some cost consciousness for not wanting to push the envelope. If a new nacelle design drops and it does not break the bank, we are slapping it on this puppy no questions asked, but a warp factor of 8.6 for a science vessel is needless right now.