I have played them both just one time each, so I don't know them nearly as well as some people here ... and I don't really want to get into the details because I will be accused of praising and/or picking on fellow architects who are also friends and former associates. I will stick to general observations.
I played Wild Horse 3-4 years ago and Rustic Canyon over this past winter. The most obvious difference between the two was that Wild Horse (then) was in much better playing condition than Rustic Canyon (then). At Wild Horse we had very firm conditions and wind; Rustic Canyon was pretty soft and there wasn't much wind that day. Also, parts of the washes at Rustic Canyon were overgrown and roped off, which really undermines the design since those washes were intended to be playable hazards.
(Having suffered through maintenance difficulties on at least two of my better designs, I can sympathize with Gil and Geoff there.)
Wild Horse opts for 18 medium sized greens with plenty of internal contour; I don't think the strategy of driving the ball changes too much based on the pin placement, but you must drive the ball well, and you must leave your approach on the correct side of the hole.
Rustic Canyon gives the average player MUCH wider fairways (but several forced carries) and large greens; it is possible to hit a lot of greens and still post a poor score. It allows for a greater variety of options in playing the holes, but the width makes it that much more important for the golf course to play firm.
I think the contrast between the two is significant, that they offer two different viewpoints: Rustic Canyon is more about design and getting the player to think about design, while Wild Horse is more about playing golf, and getting the player to execute golf shots.
I think they are similar in terms of quality and would most likely get the same rating on the Doak scale, giving Rustic Canyon the benefit of the doubt that it isn't always as soft as the day I saw it, and the fences come down.
Honestly, what they both remind me of is High Pointe, which from me is a genuine compliment, although some would disagree. And that's sort of in line with Dave's assessment ... High Pointe was more highly regarded by some people ten years ago because it was so different, but now I've done other things which people admire more. (Except, Dave, that Rustic Canyon is not like any of the public courses in Chicago, and would have the same type of enthusiastic-but-not-unanimous following there that it does in L.A.)
That's all I intend to say on the subject; please don't ask me any detailed questions about the two courses, because it does me no good to answer.