I've worked at a TDD-focused company and it always felt like I was coding through molasses. Some of us weren't as strict about TDD and I didn't notice a difference in our code quality.
To me, doing TDD right is about having the minimum amount of testing needed to keep bug rates extremely low. It's also about keeping the test code as well factored as the production code, such that changing or refactoring the production code doesn't create disproportionate work in the test suite to bring it back in line.
An experiment I've tried repeatedly is to start a new project and shoot for zero bugs. I think I'm pretty smart, so that at first seems achievable without tests. But pretty quickly complexity increases that I at least have to manually test. And not long after that, manually testing everything gets tedious, so I have to start automating the things I am manually checking. If I keep pursuing zero bugs and feeling like I'm spending my time optimally, I keep ending back up at TDD. Maybe try that for yourself on a hobby project? You might find that the TDD-focused company was better at talking about TDD than doing it.
TDD can be nice for small modules when you have a good idea of where you want to go with your code. For large modules with a lot of unknowns it can be a pain, and in those cases I prefer testing after a first draft.
Perhaps you haven't built a module that was very large yet? Maybe try writing a large module with lots of unknowns. You might find that TDD gets in your way more than it helps in the early stages.
As to whether or not I have enough experience with TDD to judge it, I'll leave that up to you. But I've been doing TDD ~20 years, and I wrote a lot of code before that. Let me know if that's sufficient.
When you make a change to Guest, you only need to change the GuestObjectMother and any tests that may directly be involved in the change to Guest. Tests that simply require a Guest to be involved in the test probably won't have to change, as they're simply retrieving the appropriate Guest object and then handing it off to something else.
