Just don't get one too demo - then you will never know :)
Once you hear the differences you will have no choice but have to have one, I owned the 5se also and had the chance to demo the 6 THINKING the same - brand new out of the box I could already clearly hear positive SQ differences. I had a Anniversary also in my system which I could have gotten at a very attractive price - very nice but in the end I preferred the 6.
I also had a 10 which I did prefer over the Anniversary but upon listening to the 6 I found the later to offer more similarities SQ wise than differences - hence my decision to purchase the 6.
I also prefer the 6 over my highly regarded Vac pre too which cost substantially more, both Sig and Master.
Living in Canada I also face similar situation cost wise, adding currently our dollar exchange sucks.
As long as you are listening to music that's all that matters - there will always be something around the corner that offers something different.