JLS- you said you welcome constructive criticism, so here is some--
Just like you should never mix subs and sub sizes, you shouldn't mix enclosure types. (unless you're making a bandpass, but that's a whole 'nother ball game)
I don't think it will sound like garbage, per se, but I definitely don't think it will sound as good as it could, especially since the port is tuned to 42hz. The reason everyone is flaming the box with the 3 RF subs is because that port is way too long and narrow. Usually, its recommended that a port should never exceed an 8:1 ratio for length to width.