Hmm, in my opinion, I still think the US version has a one-up on the other franchises. I think some of the episodes of the current TAR:Aus have been better or just as good as that of TAR20, but the latest US season had what I thought was a diverse cast (10 minority racers, yay!), fun locations, some cool tasks & I always love me some DRAMA! The great thing going for TAR:Aus right now is that the teams I didn't particularly care for have been eliminated one after another...unlike the first Australian season where all the entertaining teams were eliminated one after another and gave us a final three that I thought were pretty bland compared to the other teams.
And having seen every episode of TAR:US, TAR:Aus, TAR:CR & TARA (most of them more than once), I don't like seeing tasks reused or even entire legs reused, which TAR:Aus did for most of the first leg of this current season and did a lot of during their first season. Most people probably don't care because they hadn't seen all the episodes or like seeing a new cast tackle old challenges, but I prefer seeing new things (which TAR:US almost always offers).
Great thing with TAR:Aus is that they get an extra 5 minutes per episode that the US version doesn't. Five minutes may not seem like much, but that's 5 more minutes to get to know the teams and maybe even get in an extra task or two, so I don't blame people for enjoying the Aussie version a little more.
But anyway, I still think TAR:US reigns supreme followed closely behind by TAR: Aus, then China Rush and then TARA (great first season, but went downhill with each season that followed). Tried watching Israel but some of their tasks just seemed too silly. Finding time to watch Norway, which seems good.