Flourite is my choice, there are some links to some pictures of the results I've had with it, including one 24 hours after setup here:
Note the 75 picture, which shows the long term results as well. No offense to anyone, but I've never experienced any clouding problems with florite as long as you set it up right, and there several other people who have not had any clouding problems either.
As for color, there is flourite red and regular flourite, which is much darker. I have no experience with Eco to compare it too, but I definitely don't like the black color, it just isn't natural looking as far as I'm concerned, but that's a matter of personal choice. Seachem in general has a very good product line for planted tanks, I use many of their products, I think the results I've had speaks itself.
Shultz Aquatic Soil is basically a fracted clay product, of which there are many out there, it's just arcillite, all are inert and provide no nutritents themselves, however, since it is a fired clay product, it won't break down, and has a very high CEC which allows bacteria to efficiently breakdown waste into useable nutrients. I've looked at other brands, the only real difference seems to be particle size and price. A local nursery chain carrys a store brand for $3.99 for a ten pound bad.
The one real drawbacks (or not) is that they seem to be light tan in color and it's generally lightweight, most who use it use a top layer of gravel to keep plants down and hide the color. At the least I'd recommend amending it with iron for the root feeders. I bought some of the local stuff, "Structure", I plan on using it in a 75 that I have to tear down anyway when I move in a couple of weeks, but I'm going to mix it 50/50 with Flourite with no top layer.I'll be starting a journal on that particular tank as I'm going to be trying a number of new things.