Parsing data, which is better??

Hello guys,

You who have years of experience, how do you think? Which built-in function is fast performing? Mid, or Instr? Because Sometimes we are able to use both of them to parse some Data. I used for my project both of them. Maybe I'm wrong but Instr seems to be slower? I'm talking when you're getting data to be parsed from the network. Maybe there is a difference between local file manipulation and remote file manipulation? Just wanted to know what people think about it?

Much appreciated your time to answer this question,which will help us (to newbies) growing and getting more and more experience.

Thanks in advance!