Vistana doesn't really advertise Fountains as I & II. As an owner, there are differences between the two.
Fountains I : villas #1301 thru 1584
Fountains II : villas #1601 thru 1730
Fountains II has the jacuzzi tub inside the master bedroom (as in the Lakes and Cascades).
Fountains I has the tub inside the master bathroom.
Pros :
Fountains I slightly larger than Fountains II.
Fountains II slightly more modern, though a tad smaller. Has in-room safe in master bedroom closet.
Cons:
Some Fountains II villas don't have a water view. They back up to a small grassy area and fence.
Even though I prefer the rooms in Fountains II more, I passed on them this summer for a Fountains I villa because they couldn't give me a water view with Fountains II. The villas that back up to grass are : #1601 thru 1612 and #1631 thru 1642 and #1655 thru 1672
So to answer your question Momofmikey......
Are they just as nice as Lakes/Cascades ? I'd say they're close (more so to the Lakes than the Cascades)---particularily Fountains II because the layout is pretty much the same as Lakes/Cascades with the jacuzzi being inside the master bedroom and having the in-room safe. They are older so they might not be quite as "fresh" looking (especially compared to the Cascades), but I was very pleasently suprised to see that upkeep in this section has been really good in recent years.
Differences are---and this may be a decision breaker for you---is that only Lakes and Cascades have elevator access. Cascades and Lakes buildings can be 4-5 stories high, while Fountains I and II are only 3 stories high but have stairs only. There is Bell service on the resort to assist you with luggage if you have a 3rd floor or, if necessary, you can request a ground floor via the Diamond Lane reservation form. I know when we traveled with my mil we requested ground floor and always had it granted. The stairs could be a little tough for senior citizens or those with small children and strollers.
You can check out my Vistana photos here if you like :
http://www.imagestation.com/album/pictures.html?id=4287948459