Just different experiences. When the fluid ones came out they were the rage. I wasn't able to afford one, but of the first 5 I knew about (all makes), four leaked. I've not used one since and still won't. I can't imagine the knock off versions for less $$ are any better in terms of QC.
The "rubber bands" have been successfully protecting even race engines of all kinds for decades. Like it or not, economical design or not, they do what they are intended to.