Hi Mike,
pretty much agree, the sgm180 is the best out of the freebies.
Some of my commercial ones don't even sound as good.
Good part is with an editor you can mix n match instruments & create your own gm bank.
I'm constantly updating mine. If I find an instrument I don't like, I replace it with an instrument from another soundfont bank.
You tend to get good and bad instruments in the gm banks.
One thing I have discovered, the larger the font, doesn't neccesarily mean it's going to sound better, & when it comes to the commercial fonts , the price doesn't always dictate the quality either.
best wishes
Rikki