I don't have Carefree Sunshine, but love the saturation of Lemon Fizz. LF has set hips pretty freely with no effort on my part in my climate, though I have not attempted to germinate anything. David, have you worked with Kordes' "Sunny Sky" (KORaruli) yet? Lacks the saturation, but purportedly another good one for passing on disease resistance (per Pierre) and it has nice form. (Kordes' site gives it their highest resistance to BS.) I don't know how its cold-hardiness compares, but would imagine it might be favorably.
[size=small][color=#669966]Zone 8 / Sunset Zn 30 (Austin, TX -- formerly New Orleans, LA)[/color][/size]