This is a personal decision-lots of people love the ATACR. I have never looked through one. However, I do prefer a front focal scope and for me it would be a no go. I've never needed more than the F-1 to shoot out to 1000 yards. I say keep what you got.
If spending $2300 is like spending $23 to you then get what ever you want. If not and you're never going to shoot 1000 yards and in truth the only reason why you want the ATACR is because its new and you like new things but have absolutely no fucking reason to have it and spending $2300 will hurt then keep what you have. Now keep in mind that the ATACR does have better glass so there is that consideration if you have eye sight problems.