Wl500 vs. Wyeast abbey Yeast

I am really concerned over yeast. I feel their is a big difference between these two yeast and many people just say "Oh just use this _____" I cant stand that kind of information. I have no idea where the info comes from so I cant validate its authenticity.
So, I would love to hear. What differences you have found between these two yeast and why? How do they perform? How do they affect taste? And so on? Do you find most of your information from brewers or science articles? I am fine with both.
Thanks!

I garner most of my yeast information from how my beers taste. I have never purchased a belgian strain of yeast, but I culture chimay yeast and keep that yeast on hand for all of my belgian yeast needs and I love this yeast. Fermetended at 65 or so it leaves a mild, spicy, earthy kind of undertone and a very clean finish. If you start cool and warm it up to temps approaching 75-80 over the course of 10-14 days you will get an awesome juicy fruit/plum time of esther profile and CRAZY attenuation. Great for a tripel. My last tripel went 1.080 down to 1.007.