It could be that the HW on the LT may not be able to attain those sustained speeds. There are many factors between wireless and wired speeds and many differences in HW as well. I don't recommend speed testing wireless due to these factors. As long as wired connected are achieving your paid ISP speeds, you'll know that the services and router is working well. Wireless can achieve those speeds however it's dependent upon configurations and what the actual HW supports and is designed to do. Example, So if you have a Iphone, they are rated at 65Mb on 2.4Ghz N mode connection rates, Since your ISP services are 90Mb, the iPhone would never report or be able to test at the 90Mb speed due to it's limitation.