BudsGunShop.com - Red Dot

I use the Truglo red dot on my sport II budsgunshop.com/catalog/product_info.php/products_id/19099/truglo_red_dot_sight)

For a high end red dot I would suggest the aimpoint micro, or Any EOTech. For Mid price I suggest vortex sparc, primary arms microdot, or holosun paralow.
For Budget options I suggest the Bushnell trs 25, or Truglo tru-brite. Depending on your intended use of the rifle, you could add a magnifier. Also if you plan on using night vision only some red dots are NV compatible.
I don't want to confuse you , but do not rule out prism scopes, especially those from Primary Arms, they are awesome and priced great.

I have two red dots. The Sig romeo is on my AR pistol and a Vortex Strikefire on my carbine. Both work well for their intended purpose. If your eyes are good, then no issues. If you have an astigmatism you may experience a "startburst" effect with a red dot. If so, then I would suggest an prism scope optic with an etched reticle like the Primary Arms offering or the Vortex Spitfire.

My personal experience over some ten+ years of using red dots has been that one gets pretty much what one pays for with red dots. I've found a good mid-range option to be the Sig Romeo 5, which has proven to be durable, reliable, and has a good battery life. I would not hesitate to purchase another one. If you choose another sight, just know there are no top notch red dots available for bargain basement prices.

My recommendation is a Primary Arms with a ACSS reticle.

Marco, I have been more than satisfied with the Sig Romeo5 : (budsgunshop.com/catalog/product_info.php/products_id/6997/sig_sauer_electro-optics_sor52001_romeo5_1x_20mm_obj_unlimited_eye_relief_2_moa) --Also you don't necessarily have to go high dollar as I also own and use without issue the TruGlo : (budsgunshop.com/catalog/product_info.php/products_id/19099/truglo_red_dot_sight)