The problem I see in using Free, is that after using Pro version, you get use to that it understands my commands without too much prompt crafting. And yes, I know to write complex prompts to get the result I need.
For ex, today I tried to fix some Python code, so in few prompts I pasted the code, the .csv file that I want to read and the error. Untill I got to the error part, chatgpt forgot how my original code looks like and was talking some general tips about the error.
So yes, Free is good for basic work that requires short memory.