Depends on the song and PV. Generally, I'm against any pornographic visuals of VOCALOIDs, especially minors, and especially Miku. I love Miku, and if anyone thinks it would be funny to show the real-life me hentai images of her, then he's a dead man.
Just like said in the terms of use, VOCALOID characters are meant to be used for musical compositions by a large community. It's the music industry, not the porn industry. It's OK to express one's sexual feelings through music, nowadays some artists even make erotic MVs. But if you want to make porn, just draw your own characters, do whatever you want with them, and let the music industry and VOCALOID fandom stay out of it. Or if you want to see a VOCALOID naked so desparately, just draw a doujin and keep it for yourself without showing it to the Internet. I knew a guy who knew Hatsune Miku years before I did - because of hentai! That's a sign that the NSFW community has gone so far that people don't know what the character's actual purpose is! In my opinion, the right holders of VOCALOID characters need to act more strict to ensure that people follow their terms of use. Amazon Germany has once removed almost every single Miku dakimakura for some reason (not the other anime ones). I don't know if Crypton was aware of it but I would appreciate to see actions like that.
However, while I'm strictly against NSFW usage of VOCALOID characters, I don't have a problem with suggestive songs at all. As stated previously, artists can express whatever they want through music, even if it's sex, political opinions or even mental issues like the suicide-factor. I don't have a problem with hearing out ones feelings, even if the lyrics use insults and a difficult language. Yes, even if I have an entirely different opinion, I can still enjoy a song, even if Miku is singing with/about some guy. Two of my favorite producers are OkameP and LamazeP - two guys with an entirely different style. OkameP writes sad metal songs about death, suicide etc. LamazeP writes happy pop and denpa songs and uses lewd puns. What they have in common what I like? Awesome music, beautiful voice tuning, emotional lyrics (depends on the song) and they both make love songs.
However there is one thing that even lyrics can ruin a song for me: discrimination against beliefs, nationalities, sexual orientations etc.
"God-slaying Machine" and "Taking Over Moscow"? Over my corpse! As an orthodox Russian, I can only sh*t on those songs.
Artists have their freedom to use VOCALOIDs however they want because, technically, VOCALOIDs are instruments and mascots, but this freedom ends once it crosses the freedom of other people (even a minority group) or breaks the terms of use, which work like human rights, which VOCALOID characters, unfortunately, don't have. If a big part of artists neglect the terms of use, it will only lead to a mass of visible NSFW content which results in the fandom being seen as a bunch of perverts, but following these terms will keep the order and secure that VOCALOIDs and their fandom will always be recognized as part of the music industry.