I don't like glass because it breaks. Seeing ones juice is over rated IMO, one can tell when a tank is getting low just buy the flavor of the vape. I won't buy a tank that doesn't offer a full metal jacket, just not worth the breakage or crakage risks.
Unfortunately, it is a slight issue with me. I can understand if you use one single flavor, You can tell by the flavor. But, I never stick with just one flavor in a tank. I am constantly mixing compatible juices in the same tank to keep the pallet ever changing. I.E. I put caramel in with a Coffee flavor, then I mix it up with a bit of creme flavor. Most of the time I use Guava with banana strawberry to create a fruity mix. I use the Pyrex glass on the aga to gague when to add a different flavor, and the flavor is ever changing. with a SS option, that's not easily done, and if I add juice when it's too low, the new flavor will over power any others. I have had only one glass tank break, and it wasn't my fault, I'm usually very easy going with my mods, and don't put them through much abuse, so glass is not an issue with me, but a sort of requirement.
The Flash-e-Vapor V2 is a great choice, tis me fav of all rba's to date, also the Aqua is a top performer, and of course the Russian/Kayfun selections, all SS tank rba's, that are tip able, and usually leak free. The flashi has never leaked on me, easy to build and fill, fantastic flavor and vape.
I already have the Aqua, but no pyrex is an issue for me.
I guess I should have stated earlier, I am not necessarily looking for a fool proof genesis system, They will almost always leak no matter what. With Genesis systems, the more leak proof you make it, the less juice flow you get. And even if you choke it down very hard, it will still leak eventually. I was looking into an alternative to the Genesis that uses a glass tank option.
The Aqua seems to be a good option, but no glass and it's dual coil. I don't want a dual coil as my main PV. I am not a cloud chaser and prefer a medium level of vape with low overhead and the ability to coil my wick/wire to match my vaping preference. Cartomizers were too limiting, and I usually burned them out when I'd go on a chain vape binge.