Sometimes it happens. Sometimes you have to edit the HTML code you worte long time ago. What to do? It's an hard decision, that have to be taken individually bearing in mind the situation.
Every time I write a new feature which involves javscript or massive css code, I need to check how much that piece of code impacts performances.
While I was searching for a tool which could retrieve some information about page load timings, I found the great phantomas. This tools is able to collect a huge amount of data regarding a specific URL. Bingo!