Yes, you can hear the difference. How good are your ears though? Can you discern the difference between DD and DTS? If you can, then you will be pleased to know that, by the numbers, the difference between lossy vs. lossless is many times greater than DD vs. DTS meaning that you will hear the difference much easier. To me, the difference between lossy vs. lossless is actually similar to the difference in clarity, definition and depth of SDTV to HDTV. Of course, any audible difference is listener/system dependent.
For comparison of HDDVD and Bluray discs, including specific reviews of video and audio performance, try highdefdigest.com. They LISTEN to all the codecs and report how they compare with each other.