I am in for 3-pos switch. Luckily my newest aquisition has six 3-pos switches:
"once a spekkie...always a spekkie"
I also picked up a DX8 for a customer build. And it has three 3-pos switches, but no side sliders.
A side slider could be an alternative to a 3 pos switch. Easy enough to distinguish.
I dont like the idea about mixing a 2 and 3pos switch ala arducopter. Lets not go down that path, pls.