I just recently went down the rabbit hole of research when I decided to buy a portable vape.
What I decided on is not really as portable as I wanted but I do have versatility. And it fits in a pocket if your pocket is big enough!
I went with a box mod, the Joyetech Cubis. 200 watts, firmware is upgradable. I am running Arctic Fox on it.
For a dry herb atomizer I chose the Divine Tribe V2. It is ceramic and rebuildable when the coil needs replacement. I wish it were larger capacity but it gives great flavorful hits.
For concentrates I chose the Humboldt Vape Tech Sai atomizer with the titanium bucket with top airflow cap. I used this for the first time last night and it works really well. Not as well as a full dab rig with a torch but you can't fit one of those in your pocket at all.
I got it all on sale a couple weeks ago for around $150.
As far as counter top vaps, I've owned and happily used an Arizer Extreme Q for about four years. Does the trick nicely...