I've never understood the fascination with cucumber. If you've got a customer in the loop actively working on or reviewing acceptance tests, cucumber is very nice. If you don't, then cucumber is a big waste of time. For some reason, cucumber was the ruby/rails "meme of the day" for a while. BDD is awesome. Webrat is awesome. So if cucumber is your first exposure to those two, then cucumber seems awesome. Do yourself a favor and try BDD & Webrat without cucumber.
If steak becomes the meme of the day, at least it isn't actively harmful like cucumber was.