I was curious about this body after stumbling across it on the marketplace and decided to get it for fun. I liked the look of it when I tried the demo but wasn't crazy about how you can't wear it outside of the area or test the deformers.
I've been using a maitreya body since they came out and am pretty happy with it. The breast shape and size limitations with maitreya are my only nitpicks but not that big of a deal. I also have a slink body which was my first mesh body and it was fine I just didn't know what I was doing with the HUD having just switched over from the system body at the time and haven't tried it for a long time.
Overall I'm pretty happy with the Legacy body and it looks like there are more clothes and content coming along for it but I don't think its ready for prime time and not going to be replacing maitreya for me right now. The look is great, I think the curves and aesthetics of it are at least as good or better than maitreya lara, the HUD works good and easy to use and the default skins are pretty nice (except the nipples).
The main downer is with the deformers. It seemed like a great thing being able to use your old clothes but it doesn't keep your new Legacy shape when you use deformers, it shrinks down to whatever must be the limit of the maitreya body, so you end up with a different shape while dressed compared to being naked. Maybe you would have better results if you used one of the included default shapes but I haven't tried these, I want to make my own adjustments. The deformers do work with most of my maitreya clothes, other than the problem I mentioned, and I have a lot clothes, including shoes (you have to remove the legacy feet or you get 4 feet). Dresses can be a little hit or miss where you might need to alpha anyway.
Still I would give it a 4/5, it's a great looking bod, hoping they update it and more stuff comes along for it. What I really want is an update for maitreya or a whole new version. There is just so much available for maitreya I don't see myself wearing the legacy on a regular basis.