This EE debate reminds me of the yearly discussion on relievers. We often say why would you take the risk of signing a reliever to a 3-5 year deal (given how volatile they are) when you can typically pull a failed starter, or someone coming back off injury off the scrap heap on a low risk, 1 year deal, who will give you 90% of the return.
We can sign a guy like Beltran, Holliday, Morales, Moss, etc. to a short term deal and hope for a 120 wRC+ season out of them, or we can take the risk on a bat only, mid 30 year old slugger who'll likely give us a 130-135 wRC+ season (in 2017 and then who knows from there).
Historically, I've preferred the low risk approach to relief pitchers and thus I think I prefer the same route for our DH. I'd rather see the money spent on younger, more versatile players.