In my opinion, there is no comparison, in the other direction. Newt arguably even did more for the conservative cause domestically than Reagan did. Newt won a historic election, made Republicans the default majority in the House after 40 years out of power and forced a Democrat president to pass conservative domestic policies by winning the argument with the American public. Show me any other Republican who helped achieve as many concrete results as Newt did. Not saying Palin hasn't been a good contributor to the cause, but Newt spent a decade working in the House to push the party's platform to the right and sell it to the American public, and then reaped the gains of achieving huge electoral success for the party for another decade after that.
Palin loses points for not trying to run for President or any office after 2008. There's talking the talk and then there's walking the walk. When good people don't run, we're left with the likes of Boehner and McConnell running the day-to-day operations. Conservatives can offer all the rhetoric they want, but it's never going to be implemented if they leave the hard job of running for office up to the career politicians.
That`s the great thing about opinions, we all have one :)