I am facing exactly the same dilemma.....
My first Cree R2 tactical 18650 flashlight - awesome
...now it looks pretty dim.
Since then I've worked my way up to an SST-50 which is awesome, but now seems normal really, however it is too bright for anything closer than 10m away so no good for most everyday things which is where my Quark AA and Fenix LD10 get most use.
The Olight SR90 looks fantastic, but it is only the Lumen junkie in my that wants one, I really have no practical need for what is a search and rescue light, but I still want one.
In many ways the progression is just like everything else in life:
you start small, looking at the bigger and better ones with jealous eyes
you get there yourself and enjoy it for a while, but...
...now it just seems normal
then you calm down a bit and just go for what you need.
So go for an SST-90 light if you want to get to the summit (and part of me will be jealous), but after that, eventually you will come back down to just what you really need even if it doesn't seem quite a bright as it used to.
Oh, and bye the way, my latest light is the PAK-Lite, with run times of months on end, this is the one you want with you when you really need light.