The only difference with my collection is lack of the new Paramount double-feature and the laserdisc - I never bought into that format as it was expensive and looked clunky.
Sure it is... at least at Amazon for now (the primary offering on the link is a MP vendor but Amazon has copies for a few cents more - click the "other offers" link on the page):
Downside is it costs as much as the 2-fer from Paramount. It also doesn't have the slipcase of the earlier...
No, I've not seen the Paramount version and likely will not as I own a copy of the Imprint release, which to me looks quite good. Based on comparisons of the Imprint WotW to the Paramount I'm guessing the two releases of When World's Collide are sourced from the same master so should look almost...