I've owned the SS7G for what seems like 2+ years. I also own 3 Filcos (2 brown, 1 fukka). My opinion is the SS7G is built very, very well. That said, I have no problem with the build quality of the Filco. On both keyboards, the keycaps are getting a little shiny. All plastic keycaps get shiny sooner or later. It does seem like the SS7G has a little heavier texture on the plastic and will prevent shininess a little longer than the Filco.
The keycap walls do seem a little thicker on the SS7G. I'm not sure what makes the Filco seem keys cheap to you, maybe it's partially the sound of the keyswitches. The cherry blues have that cheap plasticy sound.
The SS7G has a few more features than the Filco: 2 usb ports, headphone & microphone jacks, native ps/2 interface with a converter for usb, media controls accessed via fn key + F1-F6, braided cord sleeve. The num, caps, scroll lock leds are way too bright.
I'm not fond of the cherry blacks for typing, though. I prefer the browns. At first, the browns were too light, but after a few weeks of everyday use, I developed a lighter touch.
For a FPS, I'd choose the SS7G. For everyday, keying the Filco.
I didn't get any Gray keycaps with my SS7G. :-(