The lag isn't you, It's not your modem, it's gotta be the game. I have a great connection and no matter who i play or when there is still spikes of severe lag where it's impossible to play.
Don't blow alot of money on your connection unless you have more reasons than just brawl.
And seriously, WTF at this lag, I'd much rather pay money like Live than deal with this shitfest nintendo thinks is working. It takes 3-10minutes just to even find players for a match, which is bullshit cause we all know there is more than just 2 other people in the world looking to play at any point in the day. They need to fix this, it's almost not worth playing online for. Wait 10minutes to start a match, play for 2-3 until you lag out and connection is lost... great stuff.
And Ryko, those were fun matches this morning, thanks. You are insane with Ike. Not to mention I use really light characters and its just hard to avoid some of those upsmashes when on my way back down... I think you hit me with one when I was at like 40% and it knocked me out, so frustrating lol. I'm starting to get better against you when you are with Ike and I'm using Pikachu haha, pit is another story.
XI Wiki

