I too fly (normally in the circuit) at low altitudes and hoped FSX would be perfect. For the first year I was stuck with 'look alike' default airfields and rather boring scenery that dragged FR's down if I put it to full. My area of Spain is a desert in FSX, not exactly realistic!!!!!!
Remember that several airfields in the UK went up on 'platforms' when FSX came out, not sure if this has been fixed now, but it annoyed me at the time. I bought the Horizon stuff, but was always disappointed when I came into an airfields that looked so 'unreal' and it stuttered so much too. I hear it is much better now.
My FSX experience was made worse by the fact that I only fly around add-on scenery in FS9 (seldom default) , like VFR France and Godzone. Only in the past 6 months has any good FSX scenery come out, and that makes more demands on the system than the default stuff does.
I agree that
'out of the box' FSX is better (in several areas), but not enough for me to swap to, without investing a small fortune...which (because I am a lazy bugger, living here in the sun and no longer doing the dreaded 9 to 5), I no longer have. For those willing to invest, I am sure FSX will be even better with the stuff like Rick's Hawk (still hoping for an FS9 version

) is released, but I cannot justify it.