They can be a really good gun (mine is awesome), but due to sporadic quality control issues in Turkey you can end up with one that is more fit for boat anchoring than shotgunning.
Before you buy it make sure the store will take it back if there is an issue with in the first 30 days.
Keep your receipt and your box.
Follow the break in requirements in the owners manual as if the world will end if you don't. Cause if you don't do that then see the boat anchor comment above. I'm serious. 99% of the issues people have with their M2000s are caused by not following the manual and not cleaning them when first bought.
Here are some good threads from shotgunworld.com I recommend going there and seeing all the other M2000 threads.
http://www.shotgunworld.com/bbs/viewtopic.php?f=98&t=197000
http://www.shotgunworld.com/bbs/viewtopic.php?f=98&t=154531
Remember those two washers. They are very important.
So your first step: clean every moving part and lube with a lite oil.
Second step: cycle the action a few hundred times.
Third step: clean again and lube with a light grease/oil
Fourth step: shoot a few hundred rounds through it.
If there are any issues with shells not feeding look for burrs on the barrel lugs preventing the bolt from locking up.
I still need to get a spare bolt handle and file my original down a little to get the detent more secure.
The only problems I have had with mine was due to running it too dry in cold weather.