I have always loved how Slavic Romanian sounds. Well, not always... the very first time I heard it, I thought it sounded like Spanish (a language I don't like). But that changed quickly, especially when I started learning it myself. Also, I have been in love with the sound of Russian for a long time, which I never got around to learning, so Romanian is my substitute.
I certainly feel that it is more difficult than French, but easier than Russian.... in terms of the grammar. Perhaps that is partly because there are few resources for learning Romanian grammar. But yes, it is somewhat irregular (verbs, de exemplu)... this I find challenging. Most of all, the cases and pronouns! Fifty ways to say this, that, these, and those!