Personally, I avoid all the velvias for shots in which people and their skin tones are important- the colour palette just isn't nuanced enough for skin tones. I much prefer Astia 100F for that. Astia may now be the only slide film on the market today that can deliver realistic skin tones.
Velvia 100F is the least 'velviesque' of the velvias and would have the best chance at decent skin tones, but nevertheless it'd not deliver what astia can. Velvia 50 for skin tones, oh hell no!
Now for landscape, velvia 100 is my poison.
Anyway I agree that you should try all of the above and arrive at your own conclusions. I predict that you when you have people in the scene, you will like Astia for slides and pro s (160s) or the similar Kodak product for negs.