my review of omni with HVD head I have had my setup for several months. here is how it has gone for me. Carts seem to be biggest problem for me. Loading them and not burning erl etc is a steep learning curve if you are not making your own. Once loaded I find the omni works well. I have gotten some tastey hits but it seems over time after 20 hits you lose flavor. For stealth at concert or traveling it is still worth not having everything perfect to be able to enjoy. The hvd head has caused several burn outs by leaving cart on omni even with it turned off with 5 clicks. Do Not carry omni HVD with carts attached as i feel they can turn on at any time. But omni works better with HVD head then the original. Suggestions would be to finish your universal cart asap and or have a nice dabber top for individual dabs. having carts being black or a black cover shroud would make omni usable in public with out anyone knowing it not a e cig. I have found THC to be a company that stands behind product with best costumer care out there. Everytime I have had a problem it has been corrected and I have been gifted several carts as well for my trouble. I find it fun to be part of company working to perfect their product and I hope that comes soon. I rate omni a 4 out of 5 stars. will be 5 once they have carts that fill with out loss of product and taste. Keep up the great work. Would also recomend in instruction manual to give links or suggest educating by watching you tube videos etc. For folks who can pick up loaded cart at dispencary this would be a 5 star product.