Complex sentence: Web splash screens are especially inconvenient for users with slow internet connections as the first page may take longer to load or if the user has turned off rich content (such as images, Flash or Shockwave), the splash page may not load at all.
Split into simpler sentences: Web splash screens are especially inconvenient for users with slow internet connections as the first page may take longer to load. Moreover, if the user has turned off rich content (such as images, Flash or Shockwave), the splash page may not load at all.