4-bay NAS buying advice

Hi all,

I am in the process of searching for a NAS server mainly for home usage. In the future IP cameras might be connected.

I am between the following products:
1) Sinology 413
2) Synology 412+
3) Thecus N4200 Pro
4) Thecus N4800

Although QNAP servers (i.e. TS-419P II or TS-469 Pro) would be also included in the options, because of the performance/price relationship of QNAP's products I decided not to list them.

I would highly appreciate any recommendations considering performance, features, support and price factors, either on the above 4 products or any other similar product at this price level.