DESCRIPTION:
No Talking
Sorry that my playing skills are not all that great.

No post editing on the sound. Pedalboard to amp to DI box to interface. I did mess with the pickup selector a few times on accident. The pickup selection is not always consistent throughout...oh well.

Direct box comparison.
Fender American Standard Strat
Vox AC15C1 (settings the same throughout)
Pedals used:
TC Electronic Flashback (for looper only)
Boss OD3
TC Electronic Nova Mod (for tremolo effect)
TC Electronic Nova Delay
TC Electronic Hall of Fame (toneprint editor)

H&K Redbox $99.00
As long as you do not need to have a load, I think this little guy is the best bang for the buck. Although the sound is different, it sounds great. The -26db pad is very handy.

Koch Dummy Box Studio $249.00
This box added some grit to the sound. It was a good sound, but probably not best if you need clean. It did seem to respond dynamically, though. The lighter you played the cleaner the sound. I really like the tone of this box and I love how small it is.

Palmer PGA-04 $679.95
This box seems to produce a slightly cleaner sound than what the amp sounds like through the actual speaker. This is my favorite DI box, but it is overpriced.

Overall, I think each piece provides unique options and sounds that make them more useful than the others in certain situations. I was surprised at how well the H&K sounded. I'll definitely be using that little guy since it can right in my guitar case. The other two are great when I need a dummy load. I would select Palmer if I needed to go really clean.

I was able to appreciate the differences after listening to this video a couple of times. Hopefully, it is helpful to someone else, too.
Please overlook the sloppy playing. My gear is certainly better than my skills.