Jake, I have a 550 FS in .308. I haven't held a 452 FS but have a friend who has both and he states that they are identical. The only mechanical difference is that the safety moves the opposite (or more common) direction on the 550 and you get a lot better looking trigger guard. Also, some calibers of the 550 have a detachable magazine, some don't. My .308 has a detachable magazine that is flush with the bottom of the stock.
I load 165 grain Sierra GameKing and 168 grain Barnes TTSX bullets to around 2550 FPS. Since my 1.5-6x40 scope cleared the iron sights with medium rings I zeroed the iron sights before mounting the scope on quick detachable rings.
For my eyes the iron sights are very good and I can easily hold about 1-1/4 to 1-1/2" at 100 yards off of a steady rest. The rifle shoots about 3/4" with the scope at the same distance since I can refine my aim a little better. With both sights I'm zeroed a little less than 3" high at 100 yards which keeps the bullets from both loads within 3" of the line of sight to about 230 yards and allows me to switch ammo without changing zeros.
Hope all this helps.
I'm saving my nickels and dimes and get a 452 FS in .22 LR so that my small game and groundhog rifle helps me practice for deer and bear.
Have a great Thanksgiving.
Lance
