IMPORTANT Filter Questions?

Hi yahoo community i have a 55 gallon freshwater planted tank. i was running 2 penguin 350 power filters on it. If you are answering this question you probebly know power filters are bad for planted tanks because they create to much surface aggitation. Plus there anoying if in your bedroom!!! Well i bought a Rena FilStar XP2 and compared to some reviews i read its very quiet almost silent infact. I cant here it at all when i close my stand doors! I guess my main question is if an xp2 is enough filtration for a 55 gall tank? Ive heard people saying in reviews that they have an xp2 on a 55 but the dont say how well it works in a 55. Im currently using the power jet nozzle and there is sufficent flow but im wondering once the filter matures will the flow still be enough? Does anyone have one that can tell me? I also have a small co2 injected powerhead in the tank its made by red sea. The 2 penguins were 350gph a piece and the rena xp2 is 300gph. Please i need personal experience!! THX!