So much depends upon your own foot shape, the particular last used and I'm finding now, even in the newer liner materials.
I'm a 44 in the Scarpa Charmoz, A 44.5 in the red Trango Evo GTX's, which through long use and wear seem minimum fit.
When Amazon recently had some selection in their $187 spin-off of the Phantom Lites, just on spec I bought a 43 & a 44.
Turns out the 43's are a great technical fit with a thin SmtWl liner sock. The 44's are great relaxed with one big sock.
A big influence on the fit of Phantom Lite (and perhaps the new lighter Phantom guide?) seems to be the quilted Primaloft1 insulation. If I'd done a quick try-on in a shop, I'd have thought them too small, tight. But, after 30 minutes or so on my foot, the quilted Primaloft seems to conform, and conform well. I'm talking toe wiggle room, the whole deal.
This contrasts with everything I'd read about fitting this boot, the 2009 Phantom lite, as in "go one size larger". Not the case at all for me.
As always, the proofs in the wearing. you've got to put them on for a while and see what happens.