I'm not familiar with either of those, but I can tell you my Yami 584 plays like a dream compared to my old Armstrong 80. The Armstrong's a good solid flute, esp since my repairman tweaked it to make it more responsive. And I use it for rehearsals and practicing and most concerts outside. When I switch to my Yami the last week before a solo, runs just fly! Low notes pour out. My fingers feel the vibration of the notes. That high E sings even without the split-key.
If you can afford it, then yes. Spring for the Yami. But keep your old flute as your workhorse.
Flutes:1975 Gemeinhardt M2 in chrome nickel;1982 Armstrong 80;2006 Yamaha 584
Piccs:1978 Artley piece of crap 15 P;1982 Gemeinhardt 4S;1980s? Armstrong all wood (no model)
Bass:2006 Jupiter di Medici G0199
Treble:2009 Guo New Voice
+ many flute-cousins