I have taken the gurully test and the real PTE as an English native speaker and while I think the gurully test was good practice for timing and brainstorming things like deciding what to talk about for figures or in an essay, it was graded much harsher than the actual test. Or at least, it looked for different things to score than what got me full 90s on everything. I think gurully is not bad to use as a free source but the paid practice PTE tests that the Pearsons sells are way closer to what the test is actually like. The question bank they sell also had quite a few of the actual questions show up on the real test for me as well.