Spoke Prep Vs. Grease
 

Ok looking at Spoke prep. is there any reason to use this stuff over linseed oil or Marine Grease?

Carpet smoking check on isle one please.

I've built 3 wheelsets using a light oil (like 3 in 1) on the spoke threads.

Allow me to bless you with the benefit of my expertise:

Preparation

Spoke threads and spoke holes in the rim should generally be lubricated with light grease or oil to allow the nipples to turn freely enough to get the spokes really tight. This is less important than it used to be due to the higher quality of modern spokes, nipples and rims, but it is still a good practice. In the case of derailer rear wheels, only the right side spokes and spoke holes need to be lubricated. The left side spokes will be loose enough that it will not be hard to turn the nipples even dry, and if you grease them they may loosen up of their own accord on the road.[1]

[1] http://sheldonbrown.com/wheelbuild.html :D

I don't like spoke prep because it makes the nipples difficult to turn. This makes building the wheel a real pain, particularly if you are using thin spokes which will wind-up a lot. The nipple locking feature of spoke prep can be an advantage however if you are building a low spoke count wheel since each spoke/nipple is highly loaded which leads to a high variation in tension as the wheel roatates under the rider (which can cause nipples to loosen).

I disagree with some fine points here ... all threaded fasteners (including spokes) should be lubricated for consistency of turning and corrosion prevention. Also, the surface where the nipple and rim make contact should be lubed for the same reason. Whether you use oil or grease doesn't matter, and I can't speak to the original question about spoke prep, cause I have not used it. But I have 20-odd-year-old wheels that I can still true (galvanized and stainless), built with greased threads.

3 in 1 has probably changed formulas, but it used to be vegetable based and subject to getting gummy and useless from oxidation, so it should never be used on anything that you expect to continue to function for more than a few weeks.

I can't remember where I read it, but Spoke Prep and Linseed oil (the latter recommended by Peter White if I remember correctly) lubricate the threads at first but eventually become grabby. That way, tensioning is easy, but the wheels should stay true for a longer time.

In practice, I use grease because my wheels are used under all weather. I want to be able to readjust the spokes if and when needed 3-4 years down the road.

I've always used triflow and never had a problem. Spoke prep seems about as useful as an elephant repeller in Iceland.