I used one 30 years ago to take autopsy pictures at the National Zoo. It was handy and provided good, even light for tissue and organ pictures. I did not use it outside the lab so I cannot speak to how it works for nature photography, etc.
I have not tried one of the LED types, but use a Nikon SB-29 Ring Flash for my Projects. They are nice. The one you just bought is 1/10th the price of the Nikon Flash. I think you did well. Report back how it works out.
I've not got this unit, but a similar one (that doesn't need the hot shoe unit).
They work fine. It's not a flash and you need to watch for LED reflections on shiny objects, but other than that: great, great buy for the buck. I use it with my 50f2 and 35 f3.5 lenses just fine, and have used it with a 100 f4 Leica on bellows via adapter on the E30. Wonderful flat illumination.