In my view, Rainbow fish are amongst the best fish you can have in a planted tank.
I currently keep several species in my 180Gal tank, or trifasciata, incisus, praecox, lacoustris and inornata.
Rainbow fish are amongst the most under rated of all ornamental fish here in Australia, maybe because they are native to Australia.
Another reason might be that they don't start really showing colour till they are 6 - 12 months old and aqarium shops don't like keeping fish in their tanks too long.

Here is an example of one of my trifasciatas