i use the viper pro 2000 and love it.. i like it because they offer three different pin sizes, .029, .019, or .010. i have the .010 size because it gives me more of a view of my target especially at longer distances. i used one of the hha's a few years back but didnt like it. im not saying its a bad sight by any means, it just wasnt for me. i just couldnt get used to having only the 1 pin. i also like extreme, spott hogg, and axcel sights. if you can stand to spend the $$ for the spott hogg or the axcel you wont be disappointed.