If you mean the difference between a solid metal dish and a mesh one, it won't make any difference to your signal. As long as the holes are tiny, it reflects the same way a solid piece of metal does. Might make a slight difference in wind-loading at low wind speeds but in higher winds I understand the mesh dish will catch wind as much as a solid does. If you find a nice mesh dish, go for it. The shape of the dish is what you want to check, that the panels are not bent or have breaking/broken parts.