I take it that those tips aren't included with the assortment in the retail package? I get them tomorrow as I ordered through Amazon. They offer the easiest return option should they not meet my needs.
The SE846 are also prone to vacuum effects but a quick jiggle of them while inserted has always relieved the vacuum or in some cases, the pressure of the trapped air. I've experienced both the vacuum and pressure effects with the SE846, but not a deal breaker as I adore the signature so much. Really hoping the M9 will match or exceed them, but everyone's anatomical and neurological make up is different - we only know once we try!
I do watch a lot of movies and TV with headphones or IEMs. I hope the soundstage of the M9 is decent. I've seen many comments that the Z1R has a great soundstage. Either way, using IEMs/cans are still the simplest way for me to combat my tinnitus. Thanks for the 'tip' tip!