Good review you covered all the aspects. I prefer the 0.25 parallel myself at 50W but for some juices at 60W. It never gets hot, the air cooling is fantastic. Glad you notice the drip tip comes out, some reviewers have overlooked that but as you say it is a snug tip and double skinned so adds to the cooling effect. My favourite sub tank, my second favourite being the Cleito. The Steam Engine beats the Cleito for vape and real flavour. More clouds and a good focused stream where the Cleito provides a messy stream in terms of vape. But even with a narrower tip on the Cleito to match the Steam Engine, the Steam Engine wins in cloud volume and distance! The Cleito is okay for taste but increases any sweetness whereas the Steam Engine holds back sweetness and allows you to taste all the individual flavours in a blend. Subtle elements of some juices I can taste with the Steam Engine where many reviewers say they can only get that particular taste element by using a dripper.
I bought my SS version from a UK vendor for £19.99 and they still sell them for that price. I have the black version coming from Fasttech for just under £16 because the only black versions on sale in the UK sell for £30 which is a bit steep. Coils are hard to come by in that only a few UK vendors seem to stock them. Great tank. Thanks for publicising it!