Mellow. Adding melody is always nice, but not necessary.
The strings sort of jump in and don't fit it with the mix - they sound like they're synthetic and coming in from nowhere, instead of being in the same place as the rest of the instruments.
Writing lyrics on top of melody is a whole new level of work - having a synthetic vocalist won't necessarily make it
easier to come up with lyrics! It's sort of like writing that "Great American Novel" - just because you've read a lot of books doesn't mean it's easy to write one.
On the other hand, if you
want to write lyrics, by all means, go for it! And having a synthetic vocalist can be a lot easier than going through the effort of setting up microphones and recording - especially if your house is half as noisy as mine!
