I have the 520 plus and use it for TT on my TT bike with 7 fields including power etc. Then flip it onto my road bike and use it with the same data fields if I know the route and load maps from Strava if I fancy an explore - 530 does the same - that said battery life is good on both but is reduced when using mapping. I don’t like the bigger units but maybe they are better if you don’t race and you want a bigger screen! 