Hello my friend and welcome to the forum
I have seen mention from Propello that the smok devices are not all too practical (I cannot remember why or where he said it, you will just have to look to confirm). Some people had success with the iStick Pico. I believe the TC is alright.
A good way to check if the TC is good is to watch/read reviews done on youtube and reddit. I know "Anthony Vapes" always does reviews on the TC.
Good luck!