What are you soldering, On filters I have typically used 60/40 but on transistors at high freq I have seen chip and wire techniques, using a wire bonder
I think the point is impedence. as long as soldering does not affect impedance much, it should be ok. But if your optimum impedance is very low (say 0.7 ohm), there will be a lot of difficulties. If you doing only one circuit for testing, you can do soldering by yourself. If you need to manufacture it, you need to know how the soldering process affects your impedance.