I would prefer without hyphens but I understand using hyphens to be next best thing. This is not necessarily fact, just the situation as I have read.

I've managed to get sites ranking for the exact match with hyphens (even for double hyphens).

Of course, if it's a hugely competitive industry, then you're going to struggle, but for some phrases it does work.

most of mine have hyphens. i would prefer without the dash, but good emd's are like golddust now.