Frihost wont care (atleast as I know) but it will wast your brandwith. Also where did you get to that page I want to set it for my websites.
If the load increases to a degree whereby the server crashes or dramatically slows down, it'll care. It shouldn't do that though I it will probably increase your bandwidth usage, so if you're already nearing your limit I wouldn't choose faster.
How many pages do you have on your website? And are they dynamic; do they require a lot of time to render (like from a cms or just static .html pages)?
If you have a lot of dynamic pages, better don't select the faster option.