Hi, what are your line stats? I've seen tp-link modems go below the 6db minimum signal required to get a synch meaning people usually got a nice speed boost from regular modems. I've seen synchs as low as 4.3db with them... Might give them a try if your line stats are above 6db. I had one client mooved from a linksys modem/router to a tp-link td-8960N unit and she got bumped from 5mb to 11mb/sec. I'm not saying it's the same case everytime but if you want better speed, better give it a shot!
Attenuation: 41.1dB down, 11.6dB up.
Power: 19.3dBm down, 10.8dBm up.
Noise Margin: 7.5dB down, 9.3dB up.
Sync: 6288kbps down, 946kbps up.
Think I could do better with a TP-Link?