I'm always for more options built into the base game.
Myself I'd like sliders for more than just the body type. Personally I find the faces bland and boring without being able to adjust the facial structure. Everyone be it npc or MC looks basically the same to me since there are a limited number of face presets.
However this is one area I especially expect to see modded rather quickly come release and full modder's tools. Those who modded their Fallout games are probably familiar with the mods Better Bodies and Body Slider. Even if you didn't care for nudity in your game, you may have been using those mods since they allowed players more customization options and could be used to morph armor/clothing/etc to fit whatever body you selected.
I tend to like Sliders too. While they have the potential to allow people to create monsters of beings that couldn't be considered alive or even cause clipping issues as things are taken to an extreme, it also allows for a massive amount of customization and control in the players hand. With a careful hand, a player can create their ideal adventurer through sliders.
Additionally, while sliders can have issues, people tend to expect those issues as part and parcel with the mechanic meaning they'd likely not need to worry too much about clipping issues if there is a body type slider (even if I would prefer it not become an issue).
