I admit I wish we had more than two choices for our tech for these votes, but to be fair I think this is sorta also a warm up topic to get us back into it after the break.
Cheaper coils means more ships. More ships means ships are closer to where they need to be, which means they don't need to be as fast.
A 25% increase in cost is a bad trade for, at best, a 19% increase in speed. It could be almost the same speed even if the roll passes.
(Warp Speed Calculator gives an absolute speed of 329 for warp 6.9 vs 389 for warp 7.3, the most generous possible improvement).
You're missing the other half of the equation- crews. More hulls without the needed people to crew them are useless, and there are only so many people willing or otherwise able to be a crew member on a starship.
Further up-post, saw someone point out if we did a 1-nacelle economy hull, it'd basically move as fast as a hull with 2 normal nacelles, but much cheaper with the new coil technology. That's not to be sneezed at. There's also the possibility of a critical success, which might enhance the speed increases or mitigate the cost.
We have a real chance at a ship, with no tweaks to its propulsion system, of making warp 7.4 decades before the Enterprise, which struggled with warp 9. With propulsion tweaks, we have the potential for a crazy speed demon, especially as we're only just leaving the Ent-era.
Further up-post, saw someone point out if we did a 1-nacelle economy hull, it'd basically move as fast as a hull with 2 normal nacelles, but much cheaper with the new coil technology. That's not to be sneezed at. There's also the possibility of a critical success, which might enhance the speed increases or mitigate the cost.
We have a real chance at a ship, with no tweaks to its propulsion system, of making warp 7.4 decades before the Enterprise, which struggled with warp 9. With propulsion tweaks, we have the potential for a crazy speed demon, especially as we're only just leaving the Ent-era.
To be honest I was playing a little loose with the numbers when I said that, I remembered the -0.4 but technically you should consider the other options are also +0.4.
But I think the point still stands
The new polyferride coils should be more capable of handling extreme temperatures now, with the exterior sheathing adding an extra layer of stability to the assembly's ability to regulate thermal variances. Only the field test will tell how much the maximum warp speeds will increase for the attached ship, but there will be at least some increase. Which brings you to a more novel idea that needs to be considered.
Practically every generation of warp engine has included intercoolers, usually in the form of a solid state material with a clearly predictable thermal performance. The goal is to keep the exterior of the warp coils as "cold" as possible, as a coil approaching its maximum thermal load begins to experience micro-quench events where the subspace fields invert and damage the surrounding material. The end result of this process is a single disastrous quench event which obliterates the warp field, the associated coils, and often the nacelle housing them.
However, Yoyodyne is proposing the use of an active coolant system instead of the usual solid-state solution. By using gaseous cryonitrium and responsive pump systems, the temperature of the coils can be actively managed. While at maximum warp the temperature becomes essentially uniform within the nacelle, at lower velocities inconsistencies in the warp plasma can produce irregularities in the individual coils' performance that subtract from the effectiveness of the warp field. Theoretically speaking the use of active coolant might contribute to a more efficient warp field at lower speeds.
But if this new coolant might work, how about even more of it? By including more thermal dissipation and running the coolant through exterior 'handles' outside the main body of the nacelle, the ability of the system to manage temperature fluctuations at higher energies would be increased. The disadvantage is the added material would drive up costs, while the new intercooler technology will certainly be an engineering challenge in its own right.