How customize-able, because I doubt they are as customize-able as a TM Glock, where you can go both internally and externally crazy, turning it in something like those speedqb hicapas, you can't really do that with the VFC. Also the VFC is highly overpriced for what it is, especially the mags that cost the same as a GBBR mag, Umarex is milking everyone with their licensing.