Inside or outside which is better?

I am using a tent with a 400 HPS with a a 6" cooltube. I am currently running duct thru the tent to the outside pulling air from the room.
I have noticed that some people leave the intake end of the cooltube open pulling air from inside the tent. Here are the two reasons ive heard for in or out. Pulling from inside the tent also helps pull more air out of the whole tent including the hot air above and around the light. Pulling air from outside the tent pulls cooler air which is more efficient in cooling the light. Then some say it doesnt matter or make much of a difference
Opinions anyone ? or personal experience have tried both ?

reasons just preference, both effectively work, some people dont have the means of cooling down then light from outside of their grow area so they just take air from inside, air from outside is what i use. Its cooler so light bulb lasts longer

I have a Homebox XS tent and I'm running a 400w HPS in it. The only way I can run my setup is by pulling the air through an open end of the reflector up and out of the tent. However, if I had another port, I would definitely push the air from the outside through the reflector, up and out of the tent. The air outside the tent will always be cooler than inside when the light is running.