I have a HTC Legend running on JB. While on the same network, the same download file gets downloaded on my Legend slower than it does on my Laptop? (no change in any conditions whatsoever)
You seem to be using different measurement units, 50KBps is the same as 400Kbps. Remember that 1 Byte = 8 bits.
If that's not the case, check if your laptop is connecting using 802.11n, HTC Legend does not support 802.11n, it only supports 802.11b/g.
Download SpeedTest app from the Market. And in your laptop, go to speedtest.net.