Your question is very relative.
We are using a software and computers that people 15 years ago would dream of.
And some of the coolest music was made with "ancient" (by todays standards ) computers.
So your dilemma is a luxury issue. I have been using 8, then went to 9 and now preordered 10 before i even installed and tested 10 beta.
Simply because i trust the Ableton team. Yes it`s not perfect and i still have wishes,,, but.... Till today i enjoyed the updates so far .
If i am disappointed this time then next time i will be more critical in purchasing or not.
It is really only a money issue. If you can afford another 200 euro or what it costs then just do it. You will sooner or later so it`s only a matter of money.
i hear you used to be able to get a good out of sound of something like this:-)
"Do i NEED it?" absolutely not!. Just look and listen to the music of the last 5-6 years made on Live 9. So is 9 good enough for you? I think the answer is YES.
You can still update later . Say in one year. What you "loose" is 50 euros discount. What you win is 1 year Peaceful state of Mind.
Or you do it now. What you "loose" is 200-250 euros. What you win is the confidence that you possess the last stage of development and a few workflow enhancements .
"Will this make you write better music?" I don`t know if i believe that.
As i say. Luxury problems. I can`t really afford it and borrowed money from a friend in order to preorder. Go figure.
So if you are happy with 9 till now, what reason to rush-change that when you can do it later?
"I try to not forget that "It never stops. You will always have a pending `update` of something or a computer that is getting old....." it`s a vicious circle.
I envy those who still work with an 8 track hardware. I mean that.
Yes it is a bummer that you don`t get a higher discount with what you mention of date of purchase
I wish you the best choice and may inspiration guide you.