Trying to decide between the Screwdriver, GLV-2, and the Riva 510. Anybody with experience using these? Any replies would be helpful. I've got a Greensmoke on the way that I will more than likely send back. After watching videos reviewing different vaporizers and actually seeing the vapor production from each I've kinda narrowed it down to these three. Could somebody tell me something about the different tastes between the three? And maybe something about the ease of use, cleaning, maintenence, etc. I'm sure that all three of these are capable of big throat hits (from the amount of vapor I've seen them produce in the videos). Another thing I should mention is that costs are not a big issue. Thanks, I appreciate any replys. This forum has already taught me alot, I'm glad I found this place.