I'm still working on getting my averages down to sub 40, so I'm not pretending to be an expert cuber or anything, but I am a mathematician by schooling and I am completely color neutral. So, at the risk of getting beaten down, here's my take on the matter.
First of all, I'm not *that* great at the cross, I regularly go over five seconds, but I'm working on it, it's currently one of my areas of focus for improving my times. I have always been color neutral, it seemed to me as a beginner that it would be a tremendous disadvantage to always restrict myself to the same color for the cross, but at that time I wasn't even aware of the 8 move upper bound on the step. I realize now that the advantage is not as extreme as I naively thought back then, but I dismissing color neutrality based on summarizing Lars' analysis as a simply 1 or two move advantage is a bit naive in itself.
Like I said, I'm not great at the cross, I have trouble planning beyond four moves and beyond five becomes very ad hoc. However, you can clearly see from Lars' results that being color neutral I have an 85% chance of getting a 5 move or shorter cross. Single color solvers only have a 30% chance of getting a cross that short. I probably spend an extra 2-4 seconds inspecting all sides of the cube looking for my best color, but I'm going to find an easy one almost three times as often as if I restricted myself to white. And, after I find one, I can plan my cross in another 3-5 seconds leaving me time to (theoretically) look for an extended cross (I'm not really good enough to plan an extended cross, but someone better than I am could certainly make use of the time).
If, on the other hand, I don't find a 5 move cross, I'm still 99.97% likely to find a 6 move cross, which would be paltry for a better solver, but should be within my comfort zone in the next month or two. Additionally, look in the other direction, I'm five times more likely than a single color solver to find a 4 move or shorter cross and twice as likely to find a 2 or 1 move cross. Furthermore, if I happen to luck into a 2 or 1 or even 0 move cross, it's unimportant to me that it isn't "my color", I'm at no disadvantage solving that color than I would be with white (or green, or whatever).
There is the argument that I may have to work harder to remember what color I'm solving on F2L, and I *do* suffer from periodic cube amnesia and have to look at my top center to remind me what's on bottom, but that's getting less and less frequent as I get better at looking ahead. And I can honestly say that LL is in no way hindered by color neutrality, I don't feel I suffer in the least at recognizing the OLL's and PLL's.
So, I was mainly spurred me to write this by a comment that color neutrality "only gives you a 1 or 2 move advantage" on average. I think the statement is misleading for two reasons. It's only a one or two move advantage, but it's an advantage a whole lot of the time. And, secondly, until I get a lot better and I'm able to do my inspections in 3 seconds like I've seen "real" cubers do in video, that 2 move advantage is huge to me.
I'll admit, it may have taken me longer to get to where I am currently and I might actually be better at my longer crosses if I had gone single color, but I think in the long run it will be an aid to getting sub-20 which is where I'd like to be this time next year.
Just my thoughts as an intermediate solver, I'm happy to entertain comments and disagreements.