Hey man, so i exclusively smoke vape pens and have owned alot. Ive owned the Cloud Pen, Micro G with the screen, atmosjunior, pulsar vortex, nail attachment for the atmos, and i have a globe on the way that fits my cloud/micro G. As you can see i havnt not found one that i am completly happy with. They are all sorta good for what they are good for. The Cloud is a nice pen, its gets good and hot and does a good job with hits, only this is i think it gets too hot as it is quite harsh from time to time and can burn your throat. Also there is a wick inside the coils and the first like 10 sessions you get a little bit of battery acid taste, once that goes away its a nice pen.
As for the best material for pens. Either winterized shatter or really dry crumbly butter. Doing the iso wash is a good method but it sounds like you skipped winterizing. After you filter and have your ISO ready for evap. throw that shit in a mason jar tight and put it in the freezer for 48 hours. There are a lot of impurities (waxes, fats, what nots) that will freeze. You then want to filter it again so those frozen "what nots" are collected and not in your oil. Reason this is so important for the pens is that they get caked up and need replacing and yada yada. When u winterize it barley leaves anything left behind. And besides, winterized is soooooo potent and soooo smooth.
That was a quick run down i recommend searching out the Winterization threads on this website and read up a bit there are some details i left out.