What software do you use for synching to the R0?

[Appick]

I have a library of about 40,000 songs (about 700GO) and I've been using the free version of MediaMonkey - upto now.
For a while now I've been pesting because the computer library up date is incredibly slow (big library, so might be normal). It's the best programme that I've been able to find.
I like the layout, it reads Flac, MP3, MP4 and others natively, I used to use the tagger (that's quite powerful) until I discovered MP3Tag, and synchronising to myR0 causes no problems (I even have the cover art displayed with WMA!) but I was wondering what you guys use!
Are there other (better?) programmes? I've tried Emo (that lasted about half an hour), WMP (don't like it - I seem to remember it being very processor heavy and Flac isn't native). I've tried Clemetine and Song bird a long while back - they might be better now but I think they were very processor heavy too. Foobar's looks good but doesn't synch (unless there's a new plug-in). Most of the time I copy/paste files onto my R0, but I like to use a programme too. I don't like installing and uninstalling programmes which is why I'm looking for advice.
I have an old computer 6 years old which is why I keep mentioning processor heavy!!