MMHS I did TT6 at the normal time to prepare for an accelerated program at my local high school. After finishing, I did Level 7 but only stayed for six months. Then I started TT8 midway through Year 6 and finished it a year early, midway through Year 7.
The content was pretty easy, and I noticed they reused their material with small changes, like in their weekly tests and maybe the simulation ones too. Overall, it was alright i guess, but not too challenging