Is there any reason, other than performance, to use this:

100 allow tcp from me to any out via ext0 setup keep-state
200 allow udp from me to any out via ext0 keep-state
300 deny ip from any to any

Instead of this:

100 check-state
200 allow tcp from me to any out via ext0 setup keep-state
300 allow udp from me to any out via ext0 keep-state
400 deny ip from any to any