I am quite happy with the look of the caroliniana. The monnieri is doing fine for me right now; however I may have to get rid of it as the leaf shape appears to similar to several other plants at the present (caroliniana, R. rotundifolia, Lysimachia). But really, the caroliniana doesn't really serve as a forefround plant. I had kept caroliniana in the past with no CO2 and it was attractive; with CO2 however it is quite stunning. I think ultimately you may have good luck with either; it depends on whether you want a foreground or background plant. By the way, I found under bright light the monnieri could get a bit stemmy at times.