the 99s is definitely a solid, well made racquet and it's not a "toy or a gimmick" by any means. Take away the open pattern and it's still a solid racquet. But whether or not the 16x15 pattern works for you is a a personal thing. Hard hitters WILL go through a lot of strings. People that already have enough topspin probably won't benefit from it either.
For me, it was great, but I have moved away from the stiffer tweaner types of frames for now. The racquet definitely will benefit some people and hurt others. You just need to try it, but to make a defining black/white statement, like this poll calls for is pretty useless IMO. It's like asking " Is a 12 oz. racquet too heavy or too light"? No real answer.
Yonex Ezone AI 100 - Volkl Cyclone or Cyclone Tour at 55 lbs