Glenn, To add to what Al said, which is all very true... I'm a full convert to secondary bevels, and to tertiary bevels on steeper grinds. That puts me in the minority, but it pretty much comes down to what works for you. I have used the Michaelson school of grinds for nearly two years.
I haven't had a serious catch in at least 2 or 300 bowls, and it's not because I'm a talented turner (which I'm not) it's all because there is just less to catch, because many catches happen when the bevel hits and then the cutting edge hits. With such a short bevel it becomes hard to catch.
Another fine reason for secondary/tertiary bevels is because you can grind your primary working bevel at a much higher grit. I'm obsessive, so I grind all but my roughing gouges at 400 and 800. I grind secondary bevels at 80 every 5 or so sharpenings which makes the primary bevel fast to sharpen. I also think I get longer out of gouge than many because I sharpen at such a fine grit.
The final big standout for me is that with steeper angles (I'm partial to 50° for most turning) less bevel means tighter radiuses in the inside of bowls. The control is greater and you can start into a cut easier and exit a cut easier.
For BOB (bottom of bowl) gouges I like a 70-80° angle but I still put a secondary and often a tertiary bevel. If it's a traditional strait up grind like most BOB gouges, it can be really catchy and to a certain extent the shorter primary bevel reduces that. On the other hand, you can cut a bit higher on that strait up grind for a cleaner cut, which increases the chance of a catch, especially right at the center nib.
I can't really explain why, but I never liked a relieved Ellsworth Grind. It might just be habit, because I turned for a year or so and really worked on learning David's grind. Today I rarely ever turn with a 60° angle as it just isn't acute enough for the softer and more difficult woods I turn—which almost no else bothers to turn.
Again: you just have to try what feels right, keep at it, and check in with more experienced turners for some mentoring now and then.