The Solo is definitely more restrictive, but then again, the Inhalater which is less restrictive is more harsh. The PAX is a nightmare to clean. Maybe the Ascent will be a good option once its released but I don't think you want your Grandma to be a guinea pig. With portables its often a trade-off. Restrictive is relative as well as if you don't want to pull huge Clouds than "sipping" at a Solo isn't overly restrictive ... its only restrictive if you pull hard on it.
As I've read through this thread, the Solo came to mind early, and is a recurring thought. There are other decent options if you want a desktop vape, but for portables, I would tend to think the Solo is the easiest from a number of perspectives (easy to load, clean/maintain, easy to use ... glass stems are potentially fragile but stems for it are cheap ....)
For plug-in options the Log Vapes would seem to be good options as well as I think the HerbalAire might be a decent one but kinda' space age for Grandma with the pump and the bags and all.
Anyways ... for the price, the Solo really can't be beat and is:
- Easy to use
- Easy to load
- Easy to clean/maintain
Only cons I can think of are restricted airflow and fragility of glass stems (but they are cheap
)
If money is no issue, than the MiniVAP may be a good option too ... but it is pretty expensive.