Pros: You really do swing it like an iron; Good Distance; and Forgiving for off-center hits
Cons: Some may not like how the club looks.
This year I replaced my 3 wood and hybrids that resemble fairway woods with Ping G15 hybrids (17* and 20*). I just couldn't hit fairway woods or anything that resembled fairway woods (including hybrids) very well.
I use the 17* G15 hybrid off the tee a lot. Although I don't get quite as much distance as the 3 wood (on those odd occasions when I was able to hit it), I gained flexibility because I can hit the 17* off the turf (fairway and rough) which I could never do with the 3 wood. The 20* G15 hybrid has become my favorite overall club for long approach shots and replaced my previous hybrid that resembled a fairway wood. I'm not a big hitter so the Ping G15 hybrid provide decent distance with a lot of forgiveness from all kinds of lies. The extra loft on the 20* combined with Ping's geometry and weighting really make it easy to get the ball in the air.
I think the biggest reason I'm having more success with Ping G15s is that they are more like irons and you really do swing them like an iron. Others who prefer their irons and have similar difficulty with fairway woods really ought to consider Ping G15s.