I just recently upgraded from the Centurion 5 into an Antec 300 due to:
(I had the gray front clearview side model of the Centurion 5.)
a. No side panel venting, except I mod'ed the case to have a 120 mm video exhaust fan. (I wasn't pleased in the long run.)
b. Difficult to clean front filters in the Centurion 5.
c. Toolless component installation (Centurion 5) vs. Thunbscrew (Antec 300)
d. Even the metal side-panel Centurion 5 wasn't pleasing to me, as it was simply a video card "vent" versus fan mount.
e. The Antec 300 seems "sturdier" to me.
f. The Antec 300's solid black is more appealing to me than the gray/black of the Centurion 5.
In short, I would recommend the Antec 300 over the Centurion 5. (Can't comment on the other Coolermaster case.)
If you go for the Antec 300, do the following:
1. Buy a good CPU cooler, and strongly think about mounting it so the CPU fan blows air up to the 140 mm exhaust fan.
2. Set the included 120 mm and 140 mm Antec Tri-Cool fans to the "Low" settings.
3. Move the 120 mm Antec fan to the lower front panel intake position.
4. Purchase 2 "decent/good" 120 mm fans for the system as exhaust fans for the side panel video and rear case positions. (
a. The case is designed as a negative airflow case, meaning more air is pulled into the case by exhaust fans than is pushed into the case by fans.
b. This allows the front filter to keep "large particles" out of the case.
c. This allows the "bottom" of the case to have good airflow from front to back despite the potential blocking of "good" airflow in the middle of the case due to a long video card.
(Due to my <and seems your> budgets, I would recommend...
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103052
For no LED's and...
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103022
For LED's. (I used the LED's to provide a low blue glow.) Multiple decent fans for "shipping cost" is much better in my opinion.
5. Buy a PSU that has a top mounted 120 mm or "outside of case mounted 80 mm" exhaust fan versus an "exhaust" fan on the rear of the PSU.
6. Note: You cannot put a 3.5" drive/card reader in the Antec 300 without an adapter.