I hate it. I also hate Eloise and Louise. The WEEZ sound really turns me off. But Heloise is worse than either Eloise and Louise because I also dislike names that begin with an H, with only a few exceptions.
I really can't figure out why people like any of these names. HELL-O-WEEZ. What on earth is attractive about that? E-LO-WEEZ. Ditto. LOO-WEEZ. Again. WEEEZ. It's just awful.
Also, Heloise just makes me think of "Hints from Heloise."