You find the Solo finicky but you're considering the NO2 and the PNP? How are they less finicky? They are less prone to breaking, but the Solo is much easier to load, reload, and stir.
As for stealth, i don't consider the Genie stealth although most people won't give you a second glance if you use it in public since it looks like a regular pipe. The Lotus is much more eficient, tasty and pleasant to use though, plus you can clean it.
All in all, i think the Solo remains your best bet then, if you are not much interested in stealth and want something to use with water.
I would consider a log vape as well, to use at home, rather than a portable.
The thing is, you have the Solo and what you are looking for is what the Solo is best at. And all the other units you're interested in are worse than the Solo with water, are close to it in stealth, except the PNP which is a bit smaller and less prone to breakage which is good when out but it lack autonomy (only 45min over 120 in the Solo).
It's like you have a maxi scooter and instead of looking for something different like a trail bike, you're looking for another scooter but smaller.