Hmm, overall, I too feel this is not *the* definitive Fett statue.
To digress: I find the original PF absolutely dull and forgettable, it lacks character and Boba is all about character.
The new PF, I like it, but a friend of mine received it and he was very disappointed with it - mix of things, the PVC head with the noticeable seam udnerneath, some cheap weathering effect and stickers, the braids are quite cheap too, dull base. I thought it was a good compromise for a 500$ piece but he kinda threw me off with his impressions.
The Mythos is still the best interpretation imho but it benefits from an artistic freedom that current SW pieces just can't ejoy anymore. I'm pretty sure that artistic liberties on the Mythos line were a bit frowned upon back then, in fact the statues didn't sell out quickly at all, they sold out after release.
This XM piece, I'd rank it #2 right behind the Mythos one. Reminds me of the Jedi Academy videogame, which is an absolutely awesome game. In one mission you meet Boba and have to go through various checkpoints while he relentlessy attacks you. Basically a single big boss fight and he's tough to push back.
I'm no Boba expert so I don't see the proportions issue - looking at pics I think the helmet could be a tad bigger and his belt a tad smaller.
The sculpt is terrific, you have all the small detailing like stitches and different materials, i.e. his suit, the cape, the belts, the pouches, the knee pads, they're all sculpted simulating different materials, which is something you just don't get on mixed media. Even the newer and improved mixed media is not as precise in replicating the various materials.
Main gripe for me is still the smoke effect. It's not inherently bad for a sculpted smoke effect, but I still think that the only way to give a good sense of smoke would be through clear resin, which would be nearly impossible on this statue due to the pose. At this point I would have preferred the statue with no smoke at all, maybe just painting his back repulsors like if they were lighting up in that moment - like if he's jumping back while activating the jetpack.