One could claim that they didn't change the Star Trek formula, they just returned it to the sexploitation roots of TOS. Berman and Braga were often critisized for ignoring TOS entirely whereas Coto and Co. were praised for incorporating more from TOS into ENT. My mind says "contradication".
Han and Leah? Yeah, they were funny, but the Trip / T'Pol relationship was much better and deeper, especially in the last season.