Pros: I bought 2 Silverstone FM121 120mm case fans over a year ago from New Egg. I spent the extra dollars because I was hoping to re-use the case fans in future builds. When I attempted to re-use the fans I ran into a fragility around the attachment of the variable control wire to the fan. Over the course of a month, both variable control wires have come loose. Now, the fans are running full blast all the time. The fans are a little too loud to run at 100% all the time. Ou...
Cons: The wire connecting the variable control interface to the fan is a point of failure to be aware of.
Summary: Not adding this as a con since the fans work very well and I have been completely pleased with them but the 3 pin header they come with for power aren't really a great option. You're supposed to plug them into the fan controllers that come with them but if you don't want to use the included the fan controller, you have to use molex which means going directly into the psu which means they spin at full speed all the time. Now, not really a big deal but!
Pros: They work extremely well. I bought them to replace the two fans that came with the Corsair H75 liquid cooler because those stock ones weren't cutting it. It's been a few months now so I don't remember the exact decrease in temperature these fans produced but I want to say it was in the neighborhood of 9-12 degrees celcius.
Summary: 5 Eggs had both worked ok. I debated giving 4 eggs, knowing that I always get the one bad one in a bunch... The second one sounded like a teenager revving his engine at a stop light. The first one is nice and quiet at a fairly low speed, and is quieted than I would have expected at higher RPM's. The steel grill is nice for a fan mounted in the bottom of the case to help supply air. Make it just a touch harder for anything to drop into the blades.
Pros: Fan #1 - Quiet, moves air well, includes a steel grill. Comes with it's own speed controller.
Cons: Fan #2 - Continuously revs up and down. Could be either the fan itself or the speed controller, but I simply disconnected it rather than investigate it. A little difficult finding a good place to mount the speed controller.
Summary: The fact that they include a trim-pot to dial down the RPM's and thus quiet the noise is a very thoughtful decision on the part of the manufacturer. These are now a first choice for me for 120mm case cooling fans or for any high CFM application. I've even rigged one of these up to cool my DSL modem for my internet connection. The modem tends to run hot. I just added an old power supply and jumpered the 24-pin connector with a bent paper-clip.
Pros: These are great case cooling fans at 100+ CFM, but they are a bit loud. They can be slowed down with a trim-pot to make them more quiet but that also reduces the CFM. All in all, a first choice for me from now on for 120mm case cooling fans. I've installed four of them on one case and will likely use another four to upgrade another case I have. Excellent fans.
Cons: Loud. Noisy. But that's to be expected at the high RPM you need in a 120mm fan to push out 100+ CFM. I'm used to it but not everyone can tolerate it.
Summary: I use my original 2 fans on an old Cooler Master CPU cooler that takes 2 120-mm fans on an old LGA775 QX6700 quad extreme, that happily runs at 12x or about 3.2ghz, at a happy ~60C under full heavy load. The speed sensor wires are plugged into the cpu fan sockets. Usually pretty quiet that way?
Pros: I LOVE these fans! Bought my first pair from Newegg over 5 years ago, still running like new. They really do move some air!