After reading an article on gravity teams, I decided to try building a few myself. The result: a fantastic anti-metagame team that frustrates opponents and is a lot of fun to use. Ironically, I have only seen one other person on PO use a team based around gravity, and I must say that gravity teams seem to be very underrated.
Advantages of gravity:
No more pesky levitate or flying types-to interfere with ground-types sweeping abilities (the fact that landorus gets gravity makes this deal even sweeter). This also applies to arena trap, meaning it is the equivalent of shadow tag under gravity.
The evasiveness of all pokemon is reduced considerably, to the point where hypnosis has the equivalent of 100% accuracy. This means that you can abuse hydro pump, focus blast, fire blast, blizzard, and thunder without worrying about them missing.
Neutral priority, making it incredibly easy to set up.
Finally, there are plenty of pokemon that get this move. Blissey, sableye (with prankster, mind you), reuniclus, dusclops, starmie, the previously mentioned landorus, and many other pokemon have access to gravity, meaning you can fit it on a team without sacrificing too much.
Only lasts five turns, with no way to increase the length.
All effects apply to you as well, meaning gravity is a two-edged sword.
No ability that causes gravity upon entering the field, meaning it must be set up manually.
In conclusion, I think gravity should be exploited more often as a field effect. It is efficient to use and the results can be staggering. I would like to hear what you think about this.