Pretty much all I can comment on is the Pax, and I just ordered a Lotus yesterday (after a long time pondering my 2nd vape purchase). The Pax is great for it's simple and small form factor and yes, it is somewhat stealthy (more on that later). However, after almost 2 years using my Pax I just can't stand behind it as far as reliability. Now I must qualify that statement with the fact that it works well almost all of the time, but when it fails you are out of luck. I'm on my second unit- in two years that isn't bad- but I have also been out twice when I haven't been able to get the mouthpiece to click open. That is directly my fault because obviously I didn't keep it clean enough, but still. Also, if you don't keep it very clean and the mouthpiece lubed up, you will get the temp light issue, which actually isn't a big deal when you are using it solo, but try to share with a friend and explain to him that you need to push on the mouthpiece to keep it heating up- it's a pain and doesn't inspire confidence.
As far as stealthy- most people will tell you it's the most stealthy vape out there. I don't find it that stealthy for one reason- it takes a good minute and a half to heat up and if you have stinky flowers it's going to smell like freaking crazy during that minute and a half. I have had people tell me "That smells good buddy" while it's heating up, not even hitting it, and when you are trying to vape in public a minute and a half is an eternity.
I also do not find the Pax economical at all, and yes I do use the sandwiched screen method, but it works better with a pretty fine grind and even a half an oven ground fine is a lot of material. Also, if you use half an oven the flavor really goes fast, like in two or three draws. And if you don't keep it clean it also suffers with flavor.
When my Pax had to go back to Ploom (stopped heating completely) I came to the conclusion I needed a more reliable vape. That is when I really started to evaluate my Pax and decided if I was buying something else I wanted reliability and better flavor. Probably more than you wanted to know, but hope it helps.