Since I don't have your ears I can't tell you if you'll hear a difference or not.
Generally speaking, if the combined cost of your AV receiver + the cost of your speakers is at least $5000 (and a minimum of $1200 went to the front LR speakers alone), then yes, you should hear a difference. It has been my experience that if you spent less than that you probably won't hear a difference since the equipment isn't up to the task (due to various technobabel like harmonic distortion, noise, etc). This applies even more strictly to the speakers.
But what your ears hear or don't hear can't be said by anyone here; why not just take one of your current discs and listen to the same sample parts in both DTS and DTA-HD? (BTW, you'll potentially hear the greatest difference if the soundtrack is in DTS-HD MA rather than DTS-HD HR.)