I have a spyder TL plus with an 14 in. Carbon Fiber barrel (accurate)
Its easy to use. As long as you have one eye looking through the sight you can keep both eyes open. Huge lens. Easy to sight in and once it is your paintballs always hit their mark (unless your gun is a POS). It looks really cool. The price is great, although the 1st review says otherwiseas well as the website MSRP or whatever. I got it for $50 at I&I sports.
Nothing at all.....get it and aim for the head.
Its great, buy it. Its a great deal. Dont buy overpriced sights like the adco e-dot. The 45mm Tru-Vision get the job done.