The Rodeoh Harness is great for beginners and more experienced users alike. It's easy to use and looks sexy-- what more can you ask? It can be used either for strap-on sex or pegging. Because it looks a lot like ordinary briefs, it makes the toy you strap on seem like a natural addition to your body, which is great for gender play.

The RodeoH harness is made of soft fabric with an elastic waistband and a rubber O-ring encased in the fabric. I love the way this harness feels on: it's amazingly soft and smooth, and I've worn it as underwear all day long without being uncomfortable. There's an inner lining which also provides a back to the base of whatever toy you insert. The RodeoH is machine washable, which is another plus.

The RodeoH is different from your traditional strap-on harness-- for one thing, it doesn't have straps. Instead it's built like a pair of briefs with an O-ring in the front. I was a little skeptical of this design, since it isn't adjustable, and spent a little while debating over exactly what size I should get. But in practice it works very well.
The one real drawback for those who like a wide variety of toy sizes is that the rubber O-ring is completely encased in fabric and impossible to switch. I found that this harness worked well with a toy of 1.25" diameter, though it was a little small and able to twist sideways a little bit. It also worked with another dildo of 1.6" diameter. It took a minute to slide that one in, but the material it was made of had a little give, so it wasn't too difficult. I would say that toys of 1.75" diameter or more would be too large for this harness, though I don't have any of that size to test it and be sure. So this might not be the best harness if you love larger dildos. Something of a small diameter (say 1") would fit but might slide around a little. Also, a larger and stiffer base will help you have more control.
One thing I noticed when using this harness is that it gives me a little less control over the dildo than my more usual two-strap harness, in a very specific way. When I pull back, the fabric of the harness stretches slightly and it takes a minute for the toy to follow me. This feels a little strange and made it harder for me to thrust very quickly, but after I'd used the harness a few times I was used to it. It didn't interfere with sex, it just felt a little different. I don't think this was a question of the right size-- it seems to be just a feature of the material and design.

I briefly debated which size to get, and went with the slightly smaller waist size. That seems to be the right choice-- the waistband is fairly tight, but wide enough that it's still comfortable. I do like that there are so many options on the waist size-- there should be something for almost everyone. That said, double check your size before you order. On me the waistband sits just above my hips.
I really like the way that it fits me overall-- it's comfortable, I can wear it all day and it makes my ass look great.
The only thing that I don't like about the fit of this harness is that the O-ring is pretty high up. Unlike with my other harness, there is absolutely no way to get the base of the dildo over my clit. It still works perfectly well, and i probably have more control over the toy than if it were placed lower down, but it doesn't feel nearly as good.

I really loved using this harness-- it's extremely easy to pull on and looks great in use. It's also really easy to slip a toy in once you've put the harness on, and adjust the flap behind the O-ring to cover the base.
I did have a slight learning curve getting used to using this harness, because the toy sits higher up than with my basic two-strap harness. I also found there was a slight lag between when I pulled back and when the toy pulled back, because the material in the front of the harness had some stretch to it. But after two or three uses I barely noticed this anymore.

This toy comes with a great black drawstring pouch that says RodeoH on it and is just the right size for storage or to grab and go. It's also machine washable, which I love: I can just throw it in the washing machine in a garment bag. It should never go in the dryer, though.