Ok, I'll probably get flamed for this (avoids all fire tanks and blasters..), however...
I have have noticed that when there is a large group of heroes doing the main Rikti Invasions (not the bombs bit), the graphical lag is terrible.
Here is a slight, though probably gonna be unpopular suggestion.. Why don't we creat/use 'raid' costumes like they do on the Hami raid? I've created one identical to Hami Raid Cossy but changed the chest emblem to an 'R' instead of an 'H'. I know that not everyone will be able to do this but if you can, it should cut down on the gfx lag peeps get. All those auras,wings etc can be bad for gfx lag when loads of peeps are fighting.
For example, During a recent Atlas Park invasion, there were so many Heroes fighting that I personally was at 1-2, sometimes 3 fps. also 20s delays on power activations.
Costume of Choice (one I use).
Head:
Full Helmet - Tech Helmet - No Details
Upper Boddy:
Tights - Muscular
Shoulders - None
Belt - None
Gloves - Smooth - Full.
Lower Body:
Legs - Tights
Boots - Smooth Tights
Black Costume as main colour.
Colour of choice for following.
Chest - Stripe1
Chest Detail - 'R'
Gloves - Stripe
Pants - Stripe1
Boots - Stripe
Of course, you don't HAVE to use the above but it would help those of us who don't have, and can't currently afford the latest PC rigs