I've never used Saaz in that fashion, so I can't tell you what it'll taste/smell like, but there's no reason you can't.
I mean, if you're trying to clone Greene King Abbott Ale, you're probably a bit off the mark using Saazer instead of Kent Goldings. But there's no reason to think that your beer will be bad. Saaz is a luvverly hop, with a very fine character. It's just different from the hops we usually assume would be used for flavor/aroma additions in English or American pale ales, 'cause it isn't Goldings or Cascades.
But hell! That's why we're homebrewers! Go nuts! :fro:
I have used Saaz as a bittering hop for an IPA with excellent results. It contributes a very nice rounded bittering that complimented the East Kent Goldings used for dry hopping. Saaz can be a bit costly to use for bittering. Mine only had a AA of 3.5% and I ended up using 4 oz of it, plus an oz of EKG for dry hopping.