I had a SAM-7. I sold it to keep my calibers narrowed down. Also, I feel that an AR-15 does a much better job as an "assault rifle" than an AK-47. I doubt that I could hit a man sized target much beyond 300 yds with an AK. Spare parts for AR-15s are flooding the market. 5.56 ammo is the cartridge of the United States. You will never, ever have a problem finding it, even if certain civiliam ammo restrictions are imposed. Hell, you can probably buy .223 on the black market if one day guns and ammo are banned outright --assuming the US is still using 5.56 ammo for the military. At closer ranges, .223/5.56 ammo is flat out devistating on soft tissue targets. Lastly, the lower recoil of a .223/5.56 out of an AR-15 will allow you to stay on target during rapid fire much more easily than an AK-47. Everything from the sights to the crisp triggers of the AR-15 aids in accuracy at longer ranges.
From a pragmatic point of view, I saw no reason to stick with the AK-47. I saw no reason to own one. Even for cheap ammo, I felt that it would be much better for me to practice with the weapon that I would bring into combat than the AK, which is simply a gun for fun. Plus, I can reuse the commercial ammo for my AR-15 for reloading.
I do miss my SAM-7, but I feel better when I look at my AR-15. If you want the accuracy of the AR-15 and reliability approaching that of an AK-47, go for another good battle rifle. You can probably abuse the M1-A just as much as an AK-47 and still have flawless reliability. Battle rifles are the guns for today's minute man.
But since we are all gun nuts, an AK is ok!