Slower download speeds, same upload speeds

[ShazamKnight]

So, over the past month or so, my download speeds have lowered significantly on my computer with a wireless connection, I have replaced the wireless card inside with a brand new Edimax card, so I think it may be the router, but I'm not too great with networking hardware.
I was wondering if a wireless router can affect DL speeds but not the upload speeds.

 

[ShazamKnight]

Also, I was thinking of getting this router just so my brands match up between my card and router, was also wondering if this router would work with a PS3 and XBOX 360 connection, (note, i have the older model of 360 with the added on wireless adapter) http://www.newegg.com/Product/Product.aspx?Item=N82E16833315105&RandomID=759599818412821120120608215336

This is my wireless card http://www.newegg.com/Product/Product.aspx?Item=N82E16833315099