I am currently on a search for a new case. And those two grabbed my attention.
Fractal Design Define R4:
+ clean lines, silent, having white version
- warm, only 2 fans
Fractal Design Arc Midi R2
+ good airflow, simplistic, 3 fans included
- no sound reduction
In my country they are about the same price, the Define being more expansive with 3-4$. Really want the Define R4's silence, but also want the airflow of the Midi R2...I like the option of moving HDD bays, i like the fans, i like the integrated fan controller, i like the SSD mounts on the back, so i'll have only HDD in the bay... But this is the same for both cases...
The Define R4 has plenty of cooling ability for any but the most extreme setups. I'm guessing you're not looking to build something very extreme.
Getting an extra fan for the second front intake can be a good idea in general. Not so much out of necessity, but to both sure that most if the air coming into the case passes a filter and increasing the chances of the airflow being good enough with all fans at low speed. The included fans are good so another of the same kind would be a good choice. (Silent Series R2 140 mm)
Well it obviously depends on what you want to do with it, but my experience with the Define R4 is pretty good.
I've added a second intake fan to the front (same as the included ones) and with a Noctua NH-U12P SE2 my 4670k at 4.2 (1.19) is between 31 (idle) and 58 (max when gaming) on the hottest core. IntelBurn at Extreme got it to 79.
But I have to say that at max speed the fans are quite audible, albeit not annoying. At 7 V I'm hard pressed to hear them and at the lowest speed they are dead silent.
Otherwise I'm pretty happy with it, maybe I'll get some Noctua fans as a replacement, but it was a good buy. And I especially like the understated design.