BP, yeah the flat water boards are nice to paddle. They can actually add another dimension to SUP, and when the surf is crappy, small, onshore, etc, you will get the brain working, and go to other destinations and still go for a paddle.
The flat water distance boards also give you a little bit more motivation to "go the extra mile" pardon the pun !

.... get onto google earth and start tracing and measuring some paddles you would like to do, or retrace a paddle you did do, to get a measurement on it.