Yes, it is true that the Slingbox's signal will be sent from your home router, to the modem, to our servers (Internet), then back down to you wherever you are. If you have low upload speed at the Slingbox location and/or low download speed at your remote location, then your viewing experience is likely to suffer. A general rule of thumb for the best HD viewing with any and all of our Slingboxes would be to have 2.5Mbps Upload and 2.5Mbps Download (though this is the maximum requirement for the best HD).
Hope this answered your question.
Sling Media Forum Moderation Team