I've got four slingboxes setup around the globe and can't say that the DVR that is in place has been produced and slowdown or streaming impact. Of course, CONTROL functions back to the DVR, channel changes, bring up list, setup recording, etc., take a second or two to respond, but it shouldn't affect the ultimate streaming performance.

Pretty much everywhere I go, I get the maximum out of my home, which is about 1MB. good enough for their "hd" stream from a slingbox proHD. Of course on a plane, I've simply put it down to low quality on purpose, or even just switched to audio if I'm trying to listen to something. Best thing on a plane I have found is simply to use one of the mobile apps, iphone, android, winmo, ipad, which will pretty much auto-throttle best performance based on your inbound stream quality.