well, they arrived and I already mounted them
what a difference! the sound has changed a lot, and for the first twenty minutes I was on the "I don't like it" side! however, after a bit of strumming and settleing, I understood why many are loyal to fluorocarbons.
1) the sound is snappy and middy, not that bright (but we are talking about a mahogany uke), but finally clear and clean while strumming. at first it seemd to be a little "dry" and "cold", but after a while probably the uke got used to them and the sound became fuller and richer, but still brighter and with less basses than with the Aquilas.
it doesn't "howl" anymore, every note is clear and can be heard while strumming or fingepicking, and the overall volume is balanced.
2) the intonation is perfect, more precise than Aquilas, and they started to stay in tune very fast. in less than two hours the tuning lasted for couple of songs. I then left the uke for some hours alone, and they just detuned a bit.
as I red, it's easier to tune the fluorocarbons with friction tuners.
3) I get some buzzes on the C string while strumming, but I think that they don't come from the frets, but from the bridge. it buzzes, when I strum hard or pluck very hard, even on the open string, so I guess it's the smaller gauge string not sitting perfectly on the bridge saddle, but I'll check better tomorrow.
4) the feeling is strange. at first they seemed to be "grippy" and hard, but after a some songs I got used to the gauge/tension and they actually are easier to press.
they don't feel like "wax" as the Super Nylgut do, but they are smooth and easy to slide.
I don't know, now, if I'd look for other fluorocarbons out there, because these D'Addario sound pretty well.
PS:
MOST IMPORTANT THING, I bought the EJ99SC, Soprano/Concert, and
the strings are long enough for two stringing, but only if you are precise mounting them.
my Ohana has the vintage bridge that only needs a small knot on the string, so I can save lenght by doing the know at the very edge; by checking the lenght comparing old strings, I got the precise lenght for the right winding on the tuners, and to cut a second string with enough lenght for another stringing on a soprano.
tomorrow I'll try them on my cheap Arrow, to see if they work well on it or if Aquilas are better on a cheap soprano.
however, if the Tenor set has the exact same gauges and doesn't cost more (here it doesn't), one can buy it and be sure to have two sets for sopranos, and maybe for concert.