I've used both. Can't say I've seen a lot of difference, but I haven't checked carefully . . .

I haven't used Mike Crashes much but Neat Video has a sharpening feature that does not affect the noise (since it knows what the noise is based on the sample) which I find very useful.

Neat works very well... but it's real slow!

I did painstaking experiments with a bunch of methods, including DNR and Neat, also several AviSynth ones. Basically I aligned matching pre and post denoise clips on Vegas video tracks with "Subtract" composite mode (on upper track), then used Levels FX on the result to magnify the differences. Be sure to offset the Neat results by as many frames as the radius size (long standing Vegas issue...). Also did same (including Neat's result) in AviSynth, I wrote code to present a "video wall" of such results. Took care to ensure levels matched etc.

And of course also looked at the real results by eye (digitally-zoomed, because you never know how people are going to watch it).

Neat Video was the clear winner. I use it only with temporal denoising, radius 1 or 2, no spatial denoising (noise correction set to zero in order to disable that). I think its temporal denoising does some kind of per-pixel motion compensation - heavy! Crash's DNR is turbo speed but leaves blurry trails.

Neat sure is slow - an overnight job - but at least now I don't have that nagging doubt as to whether it's worth it. No pain, no gain. I use it all the time, e.g. for scintillating (noise...) Z1 footage in low-lit situations

I agree, Neat Video is light years ahead of Mike Crash's DNR. There is an art to getting the right noise sample in Neat Video in much the same way you have to know what audio noise sample to choose in Izotope RX. As with most things, this comes from experience. Neat Video does have tools to automate the process of finding an appropriate noise sample but after you've used it for a while you know whether to accept Neat Video's choice or find a better sample. You also learn which parameters to tweak to obtain better results. The advantage to Mike Crash's DNR is you have one slider to adjust but, as has been pointed out, the more you more noise you remove in DNR that more motion trails you get. This is a problem with any temporal noise reduction software. Neat Video is primarily spatial noise reduction software with a temporal noise reduction component.

I have tried both and Neat Video is the way to go if you want to spend the $$. I also have Neat Image and have had a lot of success with it as well (use it for still as well as image sequence import in video).