It depends, see my other posts. In some cases, open source software
is as good, or better than non-open source software. Example:
Apache. In some cases, open source software isn't as good,
for instance, MySQL vs Oracle. And in some cases, there's
little open source software available: enterprise backup solutions
for instance.
If I pick an ISP or provider of some other service, I'm more
interested in the quality of their service, than whether
they happen to use open source software or not.
Abigail