Let me start by saying that I've used a lot of gaming mice, like, over 50 of them. The Logitech g502 was always a quality mouse and tons of people love the thing just based on the design and overall quality of the mouse; That being said, there are a few things to consider if you're thinking about getting this one in particular.
The Pros of this mouse are fairly straightforward, and are as follows: - Comfortable shape for most right handed people, but should be more comfortable for people with medium to large size hands. - Good build quality which easily places it in the same category as other 'premium' around this price point or even a bit higher. - Scroll wheel: this is one of my personal favorite features of the mouse. Allows infinite scroll to get through annoying EULA pages quicker and also quickly raise or lower volume on YouTube or other video streaming sites, but without sacrificing the much needed precision of the standard mouse wheel steps. Feels satisfying to use, but it is made of metal, which leads to a negative I'll be mentioning later on. - Sensor: The Logitech Hero sensor has been tested numerous times and found to be roughly on par with the PMW3360 series sensors (including the 3366 on the original g502) while being advantageous for usage in wireless mice due to the lessened draw of power which allows for a longer battery life.
The Cons of this mouse make it hard to recommend to everyone, and are why I don't usually recommend it as a first choice.
-Weight: My god. This thing is one of the heaviest mice I've used for an extended period of time. I don't know exactly how much this weighs, but it feels pretty similar to the original, which I believe weighed in a little over 130 grams. Most gaming mice target a weight of 100g or LIGHTER, since lowering the weight of the mouse will make extended use easier and will allow for a greater degree of control. - Not a truly "safe" shape, this may or may not matter to you, but I felt that it's worth mentioning. Obviously this is a mouse for right handed people, and it may not necessarily be a great fit for you if your hands are very small (I have very small hands and cannot reach the sniper button at all, but the mouse is still comfortable).
I would say it's a top tier mouse, but only if you can look past the weight. I would recommend that, as always, if you have the ability to do so, you should go to a local store and try some of the mice out to see which feels best to you, and make your decision after you have an idea what type of mouse shape you want.
I won't recommend that you do or don't buy a product, so I'll leave it at that.