I personally returned my laggy and fast-draining Misfit Vapor 2 that I got from JB Hi Fi in July last year and paid an extra $49 to get a Fossil Sport, and I'm much happier with the purchase. Sport is very light on the wrist and minimal, though obviously not as flashy as the Misfit. Both watches were in stock in several places (listed online, so store stock may vary) over Brisbane, but I got mine from the Mt Gravatt Westfield HN store which had quite a lot in the cabinet.
As far as specs go, it's important to note that the Explorist is physically much larger and the Sport has the Wear 3100 chipset which is supposed to have much better battery and performance. It's only 512mb ram so there's definitely still performance issues but it's a noticeable step up from my Misfit. I have only had it a day so I can't comment on the battery but I'm quite sure it will be enough to get through at least a day (which the Vapor never did). Also the Sport is one of those most popular (if not the most) Wear OS watches available.
Not sure about Sport but Explorist Gen 4 battery life sucks. With most things turned off and hardly using it apart from looking at the time, it still doesn't last a day (bought less than a year before). Very poor from Fossil