Not getting Euphoria could be a benefit, your less likely to wake up by getting too excited. Most of the lucid dreams I have had, even though I know I'm dreaming, I'm still not completely aware. But in two of my lucid dreams I have been completely aware and got that rush you talk about, I don't think there's much you can do about the awareness, sometimes you are very aware other times you are not. I'm sure even people who regularly have lucid dreams have some dreams where they are not as aware as others.