The load time for your page will ultimately determine how many people visit and more importantly return to your site. If people find your site to be slow then they will look for alternatives.
A critically important aspect of your BuddyPress Social Network is the performance of the system you have put together. Page load times is something that you need to keep an eye on since adding extra plugins to any WordPress site often results in additional Database look-ups per page, thus slowing down the page load time.