I agree- there are usually some hiccups
Just be aware that with the Android dongle, you also will encounter issues.
Short of buying a newer Mac which can mirror the screen on the HDTV, you will still have to wade through shortcomings all around.
Another option would be to use a full fledged HTPC at the location(s) where you need internet. Works better than the media streamer boxes too since you can 100% control the software you employ for the task.