The terms technically resemble each other, but in my experience, "sensuous" is a less excitable term and refers to information taken in through the senses; whereas "sensual" is more provocative, even suggestive. The latter would be more pleasurable as a rule. Here's a note from my computer dictionary (New Oxford American):
usage: The words sensual and sensuous are frequently used interchangeably to mean ‘gratifying the senses,’ especially in a sexual sense. Strictly speaking, this goes against a traditional distinction, by which sensuous is a more neutral term, meaning ‘relating to the senses rather than the intellect’ ( swimming is a beautiful, sensuous experience), while sensual relates to gratification of the senses, especially sexually ( a sensual massage). In fact, the word sensuous is thought to have been invented by John Milton (1641) in a deliberate attempt to avoid the sexual overtones of sensual. In practice, the connotations are such that it is difficult to use sensuous in Milton's sense. While traditionalists struggle to maintain a distinction, the evidence suggests that the neutral use of sensuous is rare in modern English. If a neutral use is intended, it is advisable to use alternative wording.
Perhaps, "Our day at the spa was exceedingly sensuous" vs "Her whisper in my ear was so sensual I could hardly take a breath."
