Solid state stuff (e.g. TV, hot water boiler, galley range & oven) could't care less if they're on a 60 or 50 Hz system... It's only stuff with motors (e.g. pumps, hair dryers, fridge, AC compressor etc) which care about the Hz. If they're designed for 50 Hz they'll turn a bit faster if they're powered by 60 Hz and visa versa for 60 Hz stuff running on 50 Hz. Not a big deal either way IMHO.