I've used T-58 a few times and always got over 75% AA with it and sometimes over 80%, but you need to mash low and long and add sugar. However, it is powdery, so it does not settle firmly at the bottom of the keg/bottle/can. The yeast profile is rather simplistic, with pepper and a generic spiciness to it, with the fruit being subdued. It ferments quick and it is agressive while doing so. I like it for the simplicity it offers as a dry yeast. It will produce mild, Belgian-like aroma and flavour.
I've tried Danstar Abbaye a few times and I didn't like it. Something about the yeast profile did not smell, nor taste right. They however also recommend it for darker beers, which I have not tried, so that's also on my list. It was kinda sharp tasting, quite medicinal/herbal/sharp phenolic like, which was really unpleasent. I believe it did not handle hops very well: didn't pair well with 30 IBUs, did not pair well with dry hopping, no dry hopping, 40 IBUs, 15 IBUs, etc. It ferments well, good attenuation, although slower than T-58 in my limited experience.