This is for lead Metagross, not AgiliGross...I need to deal with other leads, what about MAchamp leads for example? And do the Screens work?
If you're asking about 4th gen then:
1) you can still beat Machamp leads if you pack lum berry (you're faster and MM 2hkos);
2) EQ is necessary as lead Jirachi is extremely common and since there's no team preview if your opponent has Magnezone you're doomed;
3) EQ allows you to 2hko opposing lead Gross, just run more than 12 Spe EVs so you'll outspeed most.
And, double screens Gross can work but use it only if your team is made to abuse them.
If you're playng in 5th Gen then EQ is still the best option as it gives better neutral coverage and with team preview it's pointless to talk about "leads".