Yes, FPV was the idea. I'm getting a latency of about 80ms with a 1296x730 resolution which doesn't make it competitive for racing, but hey - it looks nice.
I use the following pipeline for streaming and simultanous caputure:
raspivid -vf -hf -n --intra 5 --profile baseline -w 1296 -h 730 -b 4500000 -fps 49 -t 0 -o - | tee >(gst-launch-1.0 -v fdsrc ! h264parse ! rtph264pay config-interval=10 pt=96 ! udpsink host=192.168.1.11 port=5000) >(cat > capture.h264) > /dev/null
and display on Mac:
gst-launch-1.0 -v udpsrc port=5000 caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' ! rtph264depay ! avdec_h264 ! videoconvert! video/x-raw,width=800,height=480 ! glimagesink
I think the main part of latency comes from the encoder on the RPi which is not optimized for low latency.