I haven't actually read the commentaries as its quite different

Just bits 'n pieces and I notice the sounds were different already. Anyway, if you can buy it, the book is still good for the introductions. Lots of stories & history (whether that is proper history or not, I did not see this amount of history on tit kiu sam and the form itself before... So IMHO its worth to get for that reason alone).
A forum like this should be an excellent place to discuss stuff like this but these discussions never go really deep. Several reasons I think. First is that TSK si really different amongst lineages. Sometimes the form looks like a completely different form, other times the differences are more subtle. Often the sounds are different. Then there are many levels of understanding. And throughout all the differences I guess there is no wrong and right either. People are afraid to say things that will be taken down by others, misinterpreted, etc.
I know my understanding of the form is meager. I have so much to learn. But I do know it built my strength up. I also know if I have a shitty mood and dont feel well, doing tsk lifts me up. I also know for a while I did it wrong, it affected my overall well being in a negative way. With help from Frank I steered back in the right direction. Ultimately you will know and feel where you are on the right track, and where you need to work on. Just like on all other aspects of our art. If you are so far that you are learning tsk you also understand how these processes works and when to adjust
Oh, and take note of my second tagline, hihi.