Velvia, along with Provia and Astia, are professional films. Sensia is the only amateur slide film made by Fuji. Generally speaking, I have found that there seems to be little to no difference between amateur and professional slide films. For instance, I challenge you to see what is better about a shot taken with regular Kodachrome and Professional Kodachrome. On the other hand, there seems to be more to be gained by using professional negative film vs amateur negative film. Maybe this is because manufacturers look at anyone who shoots slide film of any kind as being higher up the 'photography food chain' than someone who just shoots amateur C41 film.
Originally Posted by Patzer
In any case, if you are looking for a good C41 film for landscapes, how about the new Ektar 100? I actually never wanted to touch C41 until I shot a roll of Ektar 25 that I got bundled with several rolls of Kodachrome 25 on ebay. And I have to say that it is the BEST C41 film I have EVER shot. It certainly comes closer than ANY other C41 film when it comes to getting the goodness of a transparency film in a C41. Of course, I don't know if the new Ektar 100 is as good (Ive not tried it yet). But if it is half as good as the old stuff, it would be worth looking into over portrait-style C41 films. I don't think it is available as 120 or sheet film, though.