I actually discovered 'phantom mode' a few years ago when I had to return my Paradigm studio/cc speaker for a new one. I was pretty bummed cause I had just gotten LOTR and was really psyched to watch it. Well, I fired it up with just my studio/100s up front and 20s in back and didn't even THINK about the center until about an hour into the flick when I took a 'drink' break. I thought to myself, 'Holy crap, I haven't even noticed that it's gone....and I even like it better for some reason!'.
With my Maggies over the past year and a half, they throw such a ridiculously large soundstage and image so well that a center was't even a thought. But if I go back to monitors - my first love - I just don't know that only two of them can really handle what I want to get out of my HT experience. I just think that three of them across the front, combined with the SVS sub, would be favorable to two.
What don't I like specifically about centers? Well, first of all it just makes more sense to me to allocate those funds toward better mains.....or better SOMETHING. Since none of the info in the soundtrack is really lost, just handled by the mains instead, I don't feel it's worth the money in most cases. I also have very good hearing. We did extensive testing when I was an undergrad in psych, and I found out that my hearing is exceptional. So I think I'm just extra sensitive to any 'difference' in the front stage. If it's not a cohesive wall of sound, I notice it. Even with the same drivers and built by the same manufacturer, a center channel just isn't going to sound the same as the mains. It may be subtle, but to me it causes it to stick out and I just don't care for that. It's just been easier to run my mains in phantom.
So, three HT-1s seems like it may do the trick. But I REALLY want a monitor that is so damn good that it really could be "the last speaker I'll ever own".....which, to most of us in audio, means that it MIGHT get us through 3-5 years before we're wanting something else lol.