Lead-free solder can be a bitch to work with for some projects due to the higher melting point, and I do keep a spool of leaded wire around for that reason - but generally speaking for most hobbyist uses it's a non-issue as long as you have a relatively modern iron that can output enough heat (and retain it).
Yeah, a good iron and wire with a decent flux core helps a lot. Lead-free solder will never melt like butter the way leaded does, but I solder with it fairly often at work and it's not a show-stopper by any means.
Flux in general is probably the most important right after making sure you have an iron capable of handling the thermal recovery (you can't get the shit to stay liquid long enough if your iron can't handle keeping temp). The difference between relying on the flux core in even my leaded solder and adding a tap of my MG Chemicals flux when making a joint is night and day.
My lead-free joints come out nicely rounded and shiny just like my leaded ones with some practice and the right consumables. But I certainly have to break out hot air station more than I would when using leaded solder to deal with larger thermal masses (and why I will still break out my spool of leaded wire on rare occasion when I'm working with temp-sensitive components and just want it on the freaking board).
