Of the LSP's you list, I'd go with Zaino for shine and durability, no question.
On the durability question, look if the sealant is designed to sheet and it stops sheeting it is dead. If a sealant is designed to bead and it stops beading, it is dead.
I'm more interested in what everyone considers to be "acceptable beading". Someone recently posted images of their ride with a certain LSP after rain and pointed to the beading as being proof that the LSP was still alive. The beads looked flat, inconsistant in size (some larger "beads" looked like they were up to an 3/4" wide). To my eyes, if I saw beading like that I would be detailing the paint again, the LSP looked dead to me.
Remember that freshly cleaned paint beads water fairly well; to my mind if the "beads" are increasing in size, irregular, with a flat profile the LSP is dead and gone. When I use the term beading, I mean small, tight, regular drops of water that "stand up" on the paint with a high profile.
I wonder if some of the debates we have here regarding the durability of some LSPs (or lack of) are really about individual definitions of beading. I rarely see images of beading attached to reviews of LSP's or any mention made of the size, shape and consistancy of the beading, all we get are comments like "still beading after 3 months".
Just a thought...