Im not sure this are the fans you wanted feedback from, as i never own a fractal with 120s, but SPCR did review the Define R3 that had different fans than the R2, so in case its the same as your, read the
SCPR Fractal Design Define R3 ATX Tower
If you are looking into extra 120mm fans, i recommend you read the
Fan Roundup #6: Scythe, Noiseblocker, Antec, Nexus, Thermalright, specially as they review 3 of what i also consider the best 120mm fans or at least very good candidates,
Nexus BASIC D12SL-12 120mm - Cheap and very decent performer, it even matches the the Fractal color theme =)
Scythe Gentle Typhoon 120 mm - hard to get the 800rpm version that spcr reviewed, but scythe GT undervolt very well in my experience with 1850rpms and 500rpm versions, so undervolt it to your liking.
Noiseblocker NB-Multiframe M12-S1, another good fan, its more 850rpm than 750rpms as rated by noiseblocker, very good tone nothing that dominates, more like a wosh at 12V, coudlnt hear ticking nor motor noise undervolting it but in my experience it only went down to 400rpms where its very quiet, above 650rpms i can notice it as front case fan, still its a very good fan imo.