You don't really have to go all the way pyrex to make sure you don't get cracks. The Valley View tanks that don't have fill holes on the side are difficult to fill as you have to slip a needle between the carto and the seal. There is no port. And you can't put a side fill hole into pyrex, unless you put some other material there, further complicating things.
I'm planning on picking up one of these.
3ml Triple V Polypro Tank As a newbie here, I've had only one Clearomizer and I killed it in 3 days with some licorice.
It's just the polycarbonate and acrylic you need to not put cinnamon/acidic things in.
Though, even with all the bad news, I'll probably pick up a E2 Appollo/Rocket tank from Rochster Vapor since they have them in colors. I'm reluctant to do so. It's not the money, it's the frustration I'd have if I had the problems I'm reading about here.