I have one of those standard colored semi-transparent driptips with the tapered mouth piece and I use heavy VG liquids (ie AVE juice and BWB primarily) and whenever I drip in them, the drop hits the side and forms an unpoppable bubble where the taper is right next to my lips that I basically have to force-blow through to get it in there. Also, the draw sucks (or doesnt, rather). I keep pulling and pulling (it is a 1.5ohm joye from puresmoker, and I know some are better than others with the draw) but I dont get really good vapor production, nothing close to my 3.2ohm 510s at 6v. I use the 1.5s at 3.7v obviously. Are there any alternative drip tips that you would recommend that are wide enough so that I can drag on it better and not experienced the "pooling-at-the-top" issue? 
