I found that even with the el-cheapo polycarbonate gold plated lenses compared to their green glass counterparts are a lot easier on the eyes. The downside is that they scratch really easily, but as long as you don't use a side loading lid, they can last a long time. I don't know how to explain why I like them...however, a glass lense will always outlast a polycarbonate lense if properly taken care of.
Right now I use an Arc One auto lense, just because the piecework job I'm doing involves a LOT of tack welds (rocket science!). I honestly prefer passive lenses simply for clarity, but it's nice that they make an auto lense that fits into a standard helmet so I don't need to track down some "super spatter deflective" specially shaped and sized cover lense! :)