Mohamed,
While the upload speed may help, you are still limited by your bandwidth no matter where your data is. If you put your data at the office with cable and, thus, more bandwidth, you will have to access it from the office with your slower DSL.
LogMeIn Ignition won't make any of the logistics and connection faster; it will just allow you to bypass opening your browser to access your office. But, once you connect, it will be the same functionality.