At this point, the bottles of Demeter Spectre are carbonated well enough and I had a chance to snap a picture and record some thoughts. Overall, I like the beer and will definitely do it again with a few alterations.
Appearance: Slightly-hazy light copper with an orange hue. Big, fluffy white head with good retention and lacing. It's a bit darker, which I was hoping for, as that somehow seems to be a bit more rustic. I think a lot of this color is attributable to the fruit juice addition, as the grain bill was pretty light. The fruit accomplished what I wanted in that regard, especially as there isn't anything that would indicate that there is juice from peaches, raspberries, and strawberries in this.
Aroma: Faintly peachy with a bit of underlying fruit and lemon. There is a bit of generic spice there as well. It's not quite phenolic, more of a very light citrus perfume, perhaps the grains of paradise. Either way, nothing specific is identifiable, which was the goal with the spice and fruit additions.
Flavor: Mildly lactic with a generic fruitiness underneath peach. Some peach pit in the finish. Would reduce peach amount by half and instead substitute apricots. Raspberry and strawberry are not specifically identifiable. Generally faint spice and fairly light on the tongue.
Mouthfeel: Body is light to medium with good carbonation. Could use a touch more wheat and grain emphasis, perhaps upping the chloride and sodium a bit. Bitterness is not particularly noticeable; probably right where I want it. Finish is lingering fruitiness with a touch of citric and lactic acid.
Overall: I think I would mess around with the water chemistry just a bit and swap the peach for apricot, but otherwise I think this is a good start and could be a pretty good beer. I think I may also add a bit more lemon zest, and a just a bit (maybe 25mL) of juice as well.