Ragnor: Maybe I've been lucky but in the last 4 years I've changed ISP 3x, each time because of a significant performance issue or problem that was taking too long to fix.
I've moved from Xnet to Telstraclear to Telecom with minimal downtime or hassle, each time I just contacted my new intended provider 10-15 days before the end of my existing billing period then after successful move rang to close my account with my ex provider.
I'm thinking about moving away from Telecom currently as we are out of contract and their current pricing (post the end of Big Time) isn't competitive for >40GB usage.
General unwillingness to change ISP when you're getting bad/poor service lets ISP's get away with it and encourages ISP's to continue as is imo.
It seems we have diametrically opposed viewpoints