I've watched about 6 reviews on the HTC One with Windows Phone. The general thing is, if you liked the M8 with Android and was thinking about going to Windows Phone, it would be a no brainer. Your getting the best of HTC hardware with Windows Phone. By the numbers and specs, with the newer CPU, it should have a better battery life then the ICON/930 and M8's Expandability, it would be epic if that is in your needs.
Also, they said the same thing about the camera, if your a Nokia owner, you have been spoiled by great cameras as the M8 has a faster camera and takes good pictures over all, it's not even close to the Nokia models (referring to the 930/ICON/1520) for picture or detail quality
You need to balance it out, If a camera is one of your top features, The ICON/930/1520 are the phone you want. If expandability is more important than the camera, the HTC one should be your choice.
Now if we could get a ICON with a 801 chip and MicroSD slot (IR on the M8 would be nice too), there would not be a choice, it would be the ultimate phone for Windows Phone....
So, yea, the ICON is still the better phone for most people.
....Speakers don't matter,I never play music without my Bluetooth headphones.
To each their own, I also use headphones when listing to music or streaming audio, no question. I am referring to the times when you want watch a quick youtube video or something on one of the social networks. With the ICON, in a room that has a little noise or people talking, with out cranking the audio, I have to cup my hands to hear the audio and it's a pain in the a$$... Never mind listening to it on the ICON, your not getting stereo (l/r channels), the "one" will give stereo in this case.
Front speakers would make my life easier on that aspect, I tend to watch a lot of podcasts and videos on my phone and don't always have headphones available.