I got a bit carried away with my teksumo and put a mini apm, GPS etc on it so its a bit on the heavy side around 850grams with a 2200mah but it still flies really nice, floats around pretty slow and with a 2826 1400kv and 8x4 it does about 55mph flat out, might stick a 2200kv on it in the future for a bit more speed. As I said I'm pretty new to wings and you sound like you have far more experience than me but I'm gonna fly the teksumo till it breaks then maybe look at a CTH pinata or maybe a monkeyblunt teksumo
Flying wings don't like heavy wing loadings! For fpv you either need a big wing or build it light!