What's not reliable about a 50 degree seat?
The funny thing is I know there are many guys out there doing some variant of a 50 on everything from street cars to their race stuff.
I've used it on 2.3 heads, and last time I checked on that engine (mid December) that head is still the best they've come up with, and it's still the best on the dyno and at the track. And that's after Esselinger squealed like a stuck pig when the found out I was not only changing their valve job, but correcting their crap CNC porting.
I know, for 100% surety, that I'm not the only one who doesn't pick a valve job based on lift. I know personally (through PM messages and such) that there are guys who are using some variant of a 50 on lift rule stuff. All under .500 lift. And it works.
I've never been fond of doing R&D for free, but I've also never sat back and let technology go by without doing my own investigation. And making my own judgment.
It doesn't take long on a flow bench to understand why steeper than 45 degree seats are becoming the norm. Irregardless of how much David Vizard and a bunch of other guys harp on low lift flow and flatter than 45 degree seats for less than .600 lift stuff.