First, the broth is very different. Ramen broth is quite "heavy," and there are actually many varieties. Pho, as far as I know, really only has 2 ~3 broths (if you can find bun bu hue, which to me is just magic...either simply a "spicy beef pho," or something else, I have no idea. Authentic version will have congealed pork blood. I've had it, but not a fan. But the broth is magic--it is the very very very best Pho I have ever had, but only at one place, in Berkely CA. The other versions of Bun bu hue...not really a fan. I stick to regular Pho everywhere else, mainly because I've only seen Bun bo hue on 3 menus around NorCal, and only one of those versions I find tolerable.).
The noodles are very very different. Pho = thin rice noodles. Ramen = ~vermicelli or various other fancy organic buckwheat or whatever noodles. Ramen is a far richer broth with an endless variety of options, Pho can be eaten anywhere, anytime, in any climate--and it's usually just garnished with basil, onion, bean sprouts, lime, jalepeno/serrano/some more appropriate pepper, on top of whatever meat options. Traditional Pho includes tendons and cartilage and such in your bowl, but you can always order without it. I think I am supposed to order it that way to consider myself "real," but I've never liked it, so I always avoid those options. Pho Ga = chicken Pho. That is really the extent of actual variety in terms of your options.
In the states, "good" Ramen can cost up to $20/bowl and even higher if you are really trying to impress the hipsters in whatever fake-ass hipster neighborhood you have found yourself. Great Pho can be had for ~$7/bowl, in a proper Pho place. Pho wins, without question, all the time. No gauntlets need to be tossed. Look for the filthy strip malls with sub-H&S conditions and evidence of unlicensed child labor: that will be your best Pho place.
None of what I say is based on anything beyond my feels and eyes and fat belly.
Being a Raleigh native, I wish I could recommend a good place, but I have really lived there in almost 20 years and pretty much everyone has moved out, and I spend nearly all of my limited NC time in Durham, which is just a shitty place. Still, I don't really know a good place, either.