I'm new to this site, so I hope you will allow me to ask some probably redundant questions that have been asked by others. I am 61 and my eyes aren't what they used to be...so I need some help with a sight I can use effectively on my MKIII 5 1/2 bull barrel stainless. I have a cheap red dot on my crossbow and it does a pretty good job. I've ordered a ATN Ultrasight. Seems to be a middle quality, general purpose red dot sight... Anyone have any experience with them?