I think gerber may be useful if (a) you're trying to bid a no-trump slam in response to a no-trump bid and (b) you're not comfortable agreeing when 4NT/5NT will be blackwood and when they're to play (or invitational/quantitative). (I think experts would play something else there, but intermediates may prefer a specific non-NT ace-ask bid.) However, I'm not sure I ever HAVE seen that come up :) I agree in any other situation there's no point playing it :)