Any opinions or past experience with either one of these red dot scopes. I am looking to buy one for the Smith & Wesson M&P15a Flat Top. The reviews that I have read state that they are both pretty good scopes for the money. I am trying to find one that would co-witness with the iron sights. Opinions or pics of these optics would be appreciated!!!

These are low end RDS.  If going this route maybe you should stick to what others are doing.  You benefit from their experiences and troubles.  You will find more who use Primary Arms and Vortex's line of RDS on this website.

Go into the Industry forums.  Check out the vendors forums.