Thank you for your comment! I prefer a lush look (as much as will be possible w/out much water, lol) so I'll probably go w/ Cup of Gold.

Maybe we're not thinking of the same Gold flower vine.

Princess flower (Tibouchina urvilleana) is another one to consider, but it does require a lot of water to keep it in good shape and blooming. (in partial shade it requires less water but then does not bloom as profusely)

If by "Cup of Gold" you mean Solandra
maxima 'Variegata', then that is an excellent choice. I had one in Venice, and it bloomed all year, was easy to take care of, and did not take over, although it was a bit slow to get started at first.Many vines grow too fast, and while passion flowers are beautiful and made great fruit, they are a huge nuisance to take care of and create a lot of dead debris that is really bad for my allergies. The fruit will also attract possums in the summer. The Solandra will make huge flowers, is easy to prune, and does not leave dead matter on the fence, and if you have a wooden fence, the passion vine will be a big problem for dead matter.

Solandra maxima does not have to be the variegated ('Variegata') form. My neighbor grows one and it is nice.

I think the larger problem with passion vines is that you will have to do something to kill the gulf fritillary caterpillars, choose a variety that is less desirable to the butterflies, or get used to just twigs on your fence. I plant my passion flower vines in a side yard, because the foliage and flowers get completely devoured by caterpillars. It is fine--that is why I planted them! But it would not as nice if I had planned the vines to be beautiful part of the landscaping...

I'm definitely getting the impression that Cup of Gold is a better vine for my purposes...I love butterflies, but I'm not so interested in setting out a buffet :)....I'd rather keep the green parts if I can!

Thank you everyone!