After checking with my car mechanic (owner of an R1100, a Suzuki 650 and a 25cc Honda scooter), I bought a pair for my bike a month or so ago. He thinks they are a good idea to protect the tubes from stone dings on the tubes, which can cause the seals to wear out prematurely.
I notice the same problems with the A&S boots that you do. (It's hard to configure them to be loose enough to slide on the tubes, but also tight enough to stay attached to the seals at the bottom.) I've tried bandaging the A&S items with old-style 2"-wide black (the newer ones are desert green) elastic velcro US Army trouser blousers (for putting trouser legs inside boots), but haven't had much luck. The elastic bands are too tight & cause the fork gaiters to ride up on the tubes, defeating the purpose of protecting the seals. Bottom line: the A&S protectors are better than nothing, but not optimal.
(BTW, A&S states in the fine print that the red color on the advertisement is for illustrative purposes only, and that their protectors come in black only.)
I want to install the bellows type, despite the high cost (about 4X the price of the A&S style). I've seen their photo in Bob's catalog, but I've never seen them in reality. Question: Do I assume correctly that it is necessary to disassemble the top of the fork assembly to install the bellows-type fork gaiters?