In my opinion yes people like more power even if they never ever tap into it. They just like to know its there. Unless you have some very power hungry, low sensitivity 4 Ohm speakers, an A52 or 5125 will handle most situations. Another way to look at it is that an A51 gives people more power to grow into for the inherent upgrade bug that we all get with our speakers.
Again, this is my take.
The A51 was the right choice for my power hungry 4 ohms Revels.
I was not considering the Halo because I did not realize that it came in black (before the web site was updated).
The other reason, is because the Halo's are very attractive and that helps with the WAF (not to be confused with WAFWarrior ).