A few of us did a group buy on the micro-mesh belts some months back. I tried them all. If you want a mirror edge, progression through each grit (a few strokes on each of them) will get it for you. To be perfectly honest, I've found that the "factory" belts last much longer than the alternative belts do. That's why WorkSharp doesn't offer the other belts, in their testing, they felt that the belt life wasn't good enough. I do all of the main sharpening with the factory belts, and use the other belts for touch ups. When I finish my supply, I think that the only ones I'm going to re-order (if any) are either the 600 or the 800 micro-mesh belts.
I get an incredibly sharp edge just using the factory belts. Popping hair or push cutting newspaper isn't an issue.
If I desired perfect, mirror, show quality edges, I wouldn't use the WorkSharp.
I'd rather spend time dulling a knife than sharpening one, and that's the niche for the WorkSharp.