I have been really impressed with the Herakles Plus using the SS coil in TC, flavor wise it is definitely one of the best tanks I own. I wasn't as impressed using the pre-installed kanthal coil, took a few tanks to break in and even then I thought it was good, just not great.
There are some out there that have gotten faulty Herk Plus tanks and are having a very different experience then we are having. In regular power mode neither the kanthal of SS coils are game changers for me but the SS in TC is. This is the first tank that I actually prefer TC over power mode, the flavor is actually better.
I have the Crown and TFV4 as well. The Crown has more airflow than the TFV4 if that is what your looking for, it is not night and day though. The TFV4 has a little better flavor for me when using the Clapton coil, my preferred coil for flavor, not for cloud production though.
I just got the Stentorian Steam Engine from VaporDNA the day before Christmas as well. So far it has been a great tank and one of the best looking tanks I own. The Steam Engine might just be my favorite new tank, time will tell. It holds 6ml while being the same size height wise as my other tanks, has just as much airflow wide open, great build quality, doesn't get hot with it's cool drip tip design and flavor and vapor production is great with the clapton coil installed. I haven't tried the other coils yet but it comes with 3 in the kit, just haven't felt the need to replace the clapton coil.
I would definitely say the Herk Plus and Steam Engine tanks are 2 of the most impressive tanks I have gotten recently.