The primary place I still use soundfonts is with the free CoolSoft VirtualMIDISynth (a very good replacement for the very bad Microsoft GS Wavetable Synth). The product web page has links to a good number of useful soundfonts.
 
http://coolsoft.altervista.org/en/virtualmidisynth
 

bitflipper
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Here's an example, a multi-miked Kawai concert grand piano (pianos are especially well-suited to the format):
 

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What a lovely instrument! My mother had it's slightly smaller (6'6"), less expensive brother. Fabulous tone for that size soundboard! Loved playing it!

Btw, presence will not use sfz bit will use sf. I'm finding it to be useful as a teaching tool.

Nobody has mentioned TX16WX
 
This is free and will load and play Soundfont 2 files and SFZ files. That is the tip of the iceberg, its a very capable program.
 
There is a "Pro" version with more features 29 Euros for non commercial use and 89 Euros for a commercial license.
 
 

I did mention that. I haven't had a chance to use it yet though. Looks like something I could get lost for hours in 

Yes. Tho most of them are converted to sfz format for easier use.

i still use soundfonts (SF2) but i never have seen a good player or plugin to load them with the complete featureset the got. Good that i still own a creative X-Fi Titanium that supports them directly. My very old Cakewalk Pro Audio 9 still is running on a windows 10 and loads all soundfonts embed in a wrk-file correctly. No chance for the newer versions Sonar X2 or even Cakewalk by BandLab. Both don't support the old wrk-files where all the soundfont related data is implemented. 
 
I have to start Pro Audio 9 in the background and load the old wrk-file so that the correct soundfont is loaded too. 
 
I already started to completly go away from Cakewalk and over to Propellerhead Reason because they do support parts of soundfonts. I can just load any patch of a soundfont directly into Reason. Still have to fix some additional informations for the modwheel but thats not so hard for most of the instruments.

I've sampled all the favourite patches of mine from my hardware synths, and saved them as soundfonts (sf2).
 
I use Samplelord as my sample player, which works well for me as I can also use it on my SMPro V-Machine.
 
I use SampleRobot to sample all my synths, and I keep all the original samples so if I ever want to switch to sfz or Kontakt, I can easily re-export the instruments. But for now, sf2 works well for me.

I gotta say, I quite like SoundFonts, provided they're already created and set up to work easily. I never did like spending the time fiddling and testing to produce my own. Otherwise I'll just go for a good sampler like ShortCircuit2

I used to love SoundFonts!  I had a nice collection, and even made a few of my own to use in my tracks.  It was a great system and I got quite a bit of mileage out of it.  I miss them, but haven't used them in years.  No particular reason aside from the fact that I have *so* many synths and samples now, of such high quality, I simply haven't had any reason to go back to SoundFonts.  That said, there's no reason it couldn't still be a good sampling platform.