What makes this setup so great is it's simple, and it doesn't involve anything other than the herb. It's not about making nice puffy clouds of vapor people can spot from miles away.
As soon as I get them I use a piece of coat hanger and punch out the little screen at the lower end of the mouthpiece - it clogs up immediately and herb basically never goes up the mouthpiece anyway. The following applies to the regular Vhit Reload and the Vhit Reload W&D.
(I don't recommend the Vhit Reload II because although it has what might be a better coil design, the mouthpiece clogs up immediately and is a royal pain to clean out.)
The design works great too - there's plenty of room in the chamber for the right amount of herb, and the mouthpiece is spring-loaded so you can plunge the herb down to the heated coil.
The coils last a long time, as long as you don't subject them to bend force by plunging too hard and/or having too much herb in the chamber. When you first get a coil, do a burn out in the open on your battery's highest power setting. That will "purify" it.
The glass section has no purpose though, except you can insert a piece of paper with a cool image on it, which makes the unit look more unique. Otherwise it has no function.
Also these are getting very hard to find. I have 3 and will probably buy a couple more and bunch more coils because I suspect they may be going obsolete. I hope that's not true but I've seen it happen before.
By the way, I've purchased many items from VapePenSales over the years and they are a very good online merchant. They also respond immediately if you ask a question and provide good answers. Thanks VPS!