I don't think you can get a right answer on that. There are other factors that play into which card is better. Such things as CPU, chipset, MB, drivers also has it's effects.
I have an Echo Mia that is excellent. I have an AP 2496 while I may not get down to 1ms of latency that is not the end of the world. I have a Tascam PCI 822 that is great. I have a Terratec EWX 2496 that I use in my everyday system that can run on 3ms and might crash on 20ms of latency.
Sometimes it's the drivers as well. Some write some very good WDM drivers.
You'll never get a correct answer. I know you've already seen different opinions if you bothered to search.
I guess the real question is how much you want to spend and then make up your own mind.
I guess as many times as it takes to get a consistent opinion, and if there isn't one, then I guess it's a non issue. Interestingly, there is a definite trend towards people being willing to pay more $$ for their high end part, than I did for my audiop. It makes me wonder why. As with all PC hardware components, there are significant performance differences THAT DO make a difference to people's experience. As I have never heard a high end RME side by side with my audiophile, I wonder what the subjective difference is . . . is all. Asking enough questions, I will eventually arrive at a conclusion without having to find a place I can compare these two options side by side.
I too am a bit frustrated when I hear people throwing numbers around (> 1.5 ms), that don't have much relationship to reality. I have read from a posting once, that my hardware sampler has a latency of 3 ms. I don't know if that value is accurate, but I have decided to accept that value as my standard for measurement.
So right now, with my current configuration my existing system with an Audiophile sound card can't deliver that type of performance. When I have some extra bucks (this might take a while, so don't look for an answer tomorrow), I am going to hire a professional sound engineer to tune (optimize for performance) my system.
If he is able to optimize my system so that it does deliver significantly superior latency, then I will post the Giga diagnostic output on this site.
As I said, in my previous posting, I don't consider the Giga system to be usable as a substitute for a piano. It works fine for playing melodic lines (which is what I believe most people raving about its performance are referring to), but once you start playing some thick chords then you start noticing its performance issues.