Which Coolermaster HAF case did you mean? There are several models.
I built two pc's using the Coolermaster HAF 932 case. One was a case mod I did that I sold. The second one is now my back-up pc. Ventilation, airflow, cooling, and cable management are excellent.
The Antec Twelve Hundred is a classic tower case with very good ventilation, airflow, and cooling. It is an older design that was quite popular with gamers and enthusiasts.
Here is a link to a Tom's Hardware technical review of pc cases published two years ago. The review included the Antec Twelve Hundred and the Coolermaster HAF 932 cases: http://www.tomshardware.com/reviews/full-tower-case,2105.html
Quite often case selection is a matter of personal preference.