That's a nice-looking rifle, and I've heard good things about the Lithgow LA101 rifles. I'd like to try one. I hear that some Aussies complain about the weight compared to a CZ 452/455, but I have no problem with an 8 lb rifle.
I have two .17 HMRs, a CZ 452 American and a CZ 455 American (with barrels, mags, etc. for .17 HMR, .22 LR, and recently bought but not yet fitted/fired .17 HM2). I do like the idea of taking one rifle with two barrels when I travel, but I also like the idea of having one rifle for a specific caliber that's set up and ready to go.
I'll likely sell my CZ 452 American... I just don't shoot it very much. I'm strongly debating either selling my Lilja .17 HM2 CZ 455/457 barrel and instead getting an unfired repro Win 52B in the safe refitted with a .17 HM2 barrel. That way I can take three rifles with me... either the Rem 541S or Kimber 82SA in .22, the Win 52 in .17 HM2, and the CZ in .17 HMR... and have a rimfire ready for all purposes.
If I only had one rifle and wanted to change calibers fairly inexpensively, the CZ 455 or 457 are hard to beat. I've found that I maintain zero with barrel changes (different scope settings for each barrel, but repeatable).