[numbskull]

My experience has been positive but not perfect.

They are a good rugged tool, and RonD has greatly improved their quality control.
The original premise of buying an expensive sealed reel that will never fail you and require no maintenance is a pipe dream, however.
Use them enough and they will eventually leak. Mine did (no damage) and Sauerkraut's did (frozen bearing).
You need to check them and maintain them....either yourself or by sending them back. Costs @$40
Accept that and you will likely be pleased.
You could fairly say exactly the same thing about a VS.
I don't think there is any major fishing advantage to one or the other (the ZB is just a little more refined), but I haven't owned a VS.

As for the Stella option. I tried that as well and although I love my 5000sw, it did leak and fail once after pretty moderate wave exposure. Shimano fixed it just fine at minor expense but with about 2 weeks turn around (all mail time).