What browser are you using? I've had no issue with general browsing... but the wifi on my three units are not so bad... I can't recall since the Firefox 20+ it pegging out the CPU. Also Android devices don't use the full desktop version of firefox like we do..
Video playback is another issue, we don't have some commercial grade decoder for h264 videos like most android devices have. I think Flash is garbage, but video playback still needs a good decoder.
Generally for youtube I use YTDownloader w/webm codec or Minitube now that is working again.