MidWI, any bow on the market these days will have enough energy to "open' any mechanical broadhead on impact, BUT getting full, or at least good, penetration is/can be an issue if your set-up doesn't have high KE energy. If your set-up is questionable forgood enough KE, then it's best to stear away from mechanical for big game.
Now for turkey, mechanical is the way to go. You want a lot of cutting surface to kill them quickly, and the required KE doesn't need to be nearly as high, and it's best(IMO) if your arrowpenetrates fully, but doesn't pass through a turkey!