I, too, found the comment "Honeymoon in Vegas 2.0" a bit odd. I saw it twice and thought it was great in many ways - terrific acting, lots of fun, great songs and music, some hilarious moments, great staging, wonderful music, with a big band on stage.
And, yes, it got well-deserved good reviews.
Where it lots out, in my opinion, is that the story itself is a little too-light, a little too predictable and a little too vanilla. Personally, I even found the name "Betsy" to be a little to 1950s, and the whole song about her to be bland. I'm a fan of composer/lyricist Jason Robert Brown, yet he blew it with Bridges of Madison County and here most of his work was great but sounded too derivative of other composers and not original enough.
Having said that, I thoroughly enjoyed it both times - I went the second time when a $4.50 ticket showed up on Gold Club, so it was clearly on its way out.
Amazing Grace, on the other hand, has none of those great qualities - it's just a bomb, yet with great talent, and I did think the set was interesting and well done. I, too, saw Dr. Zhivago and realized into the first act that it was a loser. Between the two shows there's so much talent and so much waste.